According to the Chambers Dictionary,
Prophecy is:
Inspired or prophetic utterance; prediction. 
A prophet is:
A spokesman of deity; someone who proclaims a divine message; an inspired teacher. . . . 
Jeremiah was a prophet of God:
Then spake Jeremiah unto all the princes and to all the people, saying, The LORD sent me to prophesy against this house and against this city all the words that ye have heard. Therefore now amend your ways and your doings, and obey the voice of the LORD your God; and the LORD will repent him of the evil that he hath pronounced against you. As for me, behold, I am in your hand: do with me as seemeth good and meet unto you. But know ye for certain, that if ye put me to death, ye shall surely bring innocent blood upon yourselves, and upon this city, and upon the inhabitants thereof: for of a truth the LORD hath sent me unto you to speak all these words in your ears. 
(Jeremiah 26:12-15)
Let's see what the prophet Isaiah had to say:
Keep silence before me, O islands; and let the people renew their strength: let them come near; then let them speak: let us come near together to judgment. Who raised up the righteous man from the east, called him to his foot, gave the nations before him, and made him rule over kings? he gave them as the dust to his sword, and as driven stubble to his bow. He pursued them, and passed safely; even by the way that he had not gone with his feet. Who hath wrought and done it, calling the generations from the beginning? I the LORD, the first, and with the last; I am he. The isles saw it, and feared; the ends of the earth were afraid, drew near, and came. They helped every one his neighbour; and every one said to his brother, Be of good courage. So the carpenter encouraged the goldsmith, and he that smootheth with the hammer him that smote the anvil, saying, It is ready for the soldering: and he fastened it with nails, that it should not be moved. But thou, Israel, art my servant, Jacob whom I have chosen, the seed of Abraham my friend. Thou whom I have taken from the ends of the earth, and called thee from the chief men thereof, and said unto thee, Thou art my servant; I have chosen thee, and not cast thee away. Fear thou not; for I am with thee: be not dismayed; for I am thy God: I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness. Behold, all they that were incensed against thee shall be ashamed and confounded: they shall be as nothing; and they that strive with thee shall perish. Thou shalt seek them, and shalt not find them, even them that contended with thee: they that war against thee shall be as nothing, and as a thing of nought. For I the LORD thy God will hold thy right hand, saying unto thee, Fear not; I will help thee. Fear not, thou worm Jacob, and ye men of Israel; I will help thee, saith the LORD, and thy redeemer, the Holy One of Israel. Behold, I will make thee a new sharp threshing instrument having teeth: thou shalt thresh the mountains, and beat them small, and shalt make the hills as chaff. Thou shalt fan them, and the wind shall carry them away, and the whirlwind shall scatter them: and thou shalt rejoice in the LORD, and shalt glory in the Holy One of Israel. When the poor and needy seek water, and there is none, and their tongue faileth for thirst, I the LORD will hear them, I the God of Israel will not forsake them. I will open rivers in high places, and fountains in the midst of the valleys: I will make the wilderness a pool of water, and the dry land springs of water. I will plant in the wilderness the cedar, the shittah tree, and the myrtle, and the oil tree; I will set in the desert the fir tree, and the pine, and the box tree together: That they may see, and know, and consider, and understand together, that the hand of the LORD hath done this, and the Holy One of Israel hath created it. Produce your cause, saith the LORD; bring forth your strong reasons, saith the King of Jacob. Let them bring them forth, and shew us what shall happen: let them shew the former things, what they be, that we may consider them, and know the latter end of them; or declare us things for to come. Shew the things that are to come hereafter, that we may know that ye are gods: yea, do good, or do evil, that we may be dismayed, and behold it together. Behold, ye are of nothing, and your work of nought: an abomination is he that chooseth you. I have raised up one from the north, and he shall come: from the rising of the sun shall he call upon my name: and he shall come upon princes as upon morter, and as the potter treadeth clay. Who hath declared from the beginning, that we may know? and beforetime, that we may say, He is righteous? yea, there is none that sheweth, yea, there is none that declareth, yea, there is none that heareth your words. The first shall say to Zion, Behold, behold them: and I will give to Jerusalem one that bringeth good tidings. For I beheld, and there was no man; even among them, and there was no counsellor, that, when I asked of them, could answer a word. Behold, they are all vanity; their works are nothing: their molten images are wind and confusion. 
(Isaiah 41:1-29)
Behold my servant, whom I uphold; mine elect, in whom my soul delighteth; I have put my spirit upon him: he shall bring forth judgment to the Gentiles. He shall not cry, nor lift up, nor cause his voice to be heard in the street. A bruised reed shall he not break, and the smoking flax shall he not quench: he shall bring forth judgment unto truth. He shall not fail nor be discouraged, till he have set judgment in the earth: and the isles shall wait for his law. Thus saith God the LORD, he that created the heavens, and stretched them out; he that spread forth the earth, and that which cometh out of it; he that giveth breath unto the people upon it, and spirit to them that walk therein: I the LORD have called thee in righteousness, and will hold thine hand, and will keep thee, and give thee for a covenant of the people, for a light of the Gentiles; To open the blind eyes, to bring out the prisoners from the prison, and them that sit in darkness out of the prison house. I am the LORD: that is my name: and my glory will I not give to another, neither my praise to graven images. Behold, the former things are come to pass, and new things do I declare: before they spring forth I tell you of them. Sing unto the LORD a new song, and his praise from the end of the earth, ye that go down to the sea, and all that is therein; the isles, and the inhabitants thereof. Let the wilderness and the cities thereof lift up their voice, the villages that Kedar doth inhabit: let the inhabitants of the rock sing, let them shout from the top of the mountains. Let them give glory unto the LORD, and declare his praise in the islands. The LORD shall go forth as a mighty man, he shall stir up jealousy like a man of war: he shall cry, yea, roar; he shall prevail against his enemies. I have long time holden my peace; I have been still, and refrained myself: now will I cry like a travailing woman; I will destroy and devour at once. I will make waste mountains and hills, and dry up all their herbs; and I will make the rivers islands, and I will dry up the pools. And I will bring the blind by a way that they knew not; I will lead them in paths that they have not known: I will make darkness light before them, and crooked things straight. These things will I do unto them, and not forsake them. They shall be turned back, they shall be greatly ashamed, that trust in graven images, that say to the molten images, Ye are our gods. Hear, ye deaf; and look, ye blind, that ye may see. Who is blind, but my servant? or deaf, as my messenger that I sent? who is blind as he that is perfect, and blind as the LORD'S servant? Seeing many things, but thou observest not; opening the ears, but he heareth not. The LORD is well pleased for his righteousness' sake; he will magnify the law, and make it honourable. But this is a people robbed and spoiled; they are all of them snared in holes, and they are hid in prison houses: they are for a prey, and none delivereth; for a spoil, and none saith, Restore. Who among you will give ear to this? who will hearken and hear for the time to come? Who gave Jacob for a spoil, and Israel to the robbers? did not the LORD, he against whom we have sinned? for they would not walk in his ways, neither were they obedient unto his law. Therefore he hath poured upon him the fury of his anger, and the strength of battle: and it hath set him on fire round about, yet he knew not; and it burned him, yet he laid it not to heart. 
(Isaiah 42:1-25)
But now thus saith the LORD that created thee, O Jacob, and he that formed thee, O Israel, Fear not: for I have redeemed thee, I have called thee by thy name; thou art mine. When thou passest through the waters, I will be with thee; and through the rivers, they shall not overflow thee: when thou walkest through the fire, thou shalt not be burned; neither shall the flame kindle upon thee. For I am the LORD thy God, the Holy One of Israel, thy Saviour: I gave Egypt for thy ransom, Ethiopia and Seba for thee. Since thou wast precious in my sight, thou hast been honourable, and I have loved thee: therefore will I give men for thee, and people for thy life. Fear not: for I am with thee: I will bring thy seed from the east, and gather thee from the west; I will say to the north, Give up; and to the south, Keep not back: bring my sons from far, and my daughters from the ends of the earth; Even every one that is called by my name: for I have created him for my glory, I have formed him; yea, I have made him. Bring forth the blind people that have eyes, and the deaf that have ears. Let all the nations be gathered together, and let the people be assembled: who among them can declare this, and shew us former things? let them bring forth their witnesses, that they may be justified: or let them hear, and say, It is truth. Ye are my witnesses, saith the LORD, and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me. I, even I, am the LORD; and beside me there is no saviour. I have declared, and have saved, and I have shewed, when there was no strange god among you: therefore ye are my witnesses, saith the LORD, that I am God. Yea, before the day was I am he; and there is none that can deliver out of my hand: I will work, and who shall let it? Thus saith the LORD, your redeemer, the Holy One of Israel; For your sake I have sent to Babylon, and have brought down all their nobles, and the Chaldeans, whose cry is in the ships. I am the LORD, your Holy One, the creator of Israel, your King. Thus saith the LORD, which maketh a way in the sea, and a path in the mighty waters; Which bringeth forth the chariot and horse, the army and the power; they shall lie down together, they shall not rise: they are extinct, they are quenched as tow. Remember ye not the former things, neither consider the things of old. Behold, I will do a new thing; now it shall spring forth; shall ye not know it? I will even make a way in the wilderness, and rivers in the desert. The beast of the field shall honour me, the dragons and the owls: because I give waters in the wilderness, and rivers in the desert, to give drink to my people, my chosen. This people have I formed for myself; they shall shew forth my praise. But thou hast not called upon me, O Jacob; but thou hast been weary of me, O Israel. 
(Isaiah 43:1-22)
Yet now hear, O Jacob my servant; and Israel, whom I have chosen: Thus saith the LORD that made thee, and formed thee from the womb, which will help thee; Fear not, O Jacob, my servant; and thou, Jesurun, whom I have chosen. For I will pour water upon him that is thirsty, and floods upon the dry ground: I will pour my spirit upon thy seed, and my blessing upon thine offspring: And they shall spring up as among the grass, as willows by the water courses. One shall say, I am the LORD'S; and another shall call himself by the name of Jacob; and another shall subscribe with his hand unto the LORD, and surname himself by the name of Israel. Thus saith the LORD the King of Israel, and his redeemer the LORD of hosts; I am the first, and I am the last; and beside me there is no God. And who, as I, shall call, and shall declare it, and set it in order for me, since I appointed the ancient people? and the things that are coming, and shall come, let them shew unto them. Fear ye not, neither be afraid: have not I told thee from that time, and have declared it? ye are even my witnesses. Is there a God beside me? yea, there is no God; I know not any. They that make a graven image are all of them vanity; and their delectable things shall not profit; and they are their own witnesses; they see not, nor know; that they may be ashamed. Who hath formed a god, or molten a graven image that is profitable for nothing? Behold, all his fellows shall be ashamed: and the workmen, they are of men: let them all be gathered together, let them stand up; yet they shall fear, and they shall be ashamed together. The smith with the tongs both worketh in the coals, and fashioneth it with hammers, and worketh it with the strength of his arms: yea, he is hungry, and his strength faileth: he drinketh no water, and is faint. The carpenter stretcheth out his rule; he marketh it out with a line; he fitteth it with planes, and he marketh it out with the compass, and maketh it after the figure of a man, according to the beauty of a man; that it may remain in the house. He heweth him down cedars, and taketh the cypress and the oak, which he strengtheneth for himself among the trees of the forest: he planteth an ash, and the rain doth nourish it. Then shall it be for a man to burn: for he will take thereof, and warm himself; yea, he kindleth it, and baketh bread; yea, he maketh a god, and worshippeth it; he maketh it a graven image, and falleth down thereto. He burneth part thereof in the fire; with part thereof he eateth flesh; he roasteth roast, and is satisfied: yea, he warmeth himself, and saith, Aha, I am warm, I have seen the fire: And the residue thereof he maketh a god, even his graven image: he falleth down unto it, and worshippeth it, and prayeth unto it, and saith, Deliver me; for thou art my god. They have not known nor understood: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand. And none considereth in his heart, neither is there knowledge nor understanding to say, I have burned part of it in the fire; yea, also I have baked bread upon the coals thereof; I have roasted flesh, and eaten it: and shall I make the residue thereof an abomination? shall I fall down to the stock of a tree? He feedeth on ashes: a deceived heart hath turned him aside, that he cannot deliver his soul, nor say, Is there not a lie in my right hand? Remember these, O Jacob and Israel; for thou art my servant: I have formed thee; thou art my servant: O Israel, thou shalt not be forgotten of me. I have blotted out, as a thick cloud, thy transgressions, and, as a cloud, thy sins: return unto me; for I have redeemed thee. Sing, O ye heavens; for the LORD hath done it: shout, ye lower parts of the earth: break forth into singing, ye mountains, O forest, and every tree therein: for the LORD hath redeemed Jacob, and glorified himself in Israel. Thus saith the LORD, thy redeemer, and he that formed thee from the womb, I am the LORD that maketh all things; that stretcheth forth the heavens alone; that spreadeth abroad the earth by myself; That frustrateth the tokens of the liars, and maketh diviners mad; that turneth wise men backward, and maketh their knowledge foolish; That confirmeth the word of his servant, and performeth the counsel of his messengers; that saith to Jerusalem, Thou shalt be inhabited; and to the cities of Judah, Ye shall be built, and I will raise up the decayed places thereof: That saith to the deep, Be dry, and I will dry up thy rivers: That saith of Cyrus, He is my shepherd, and shall perform all my pleasure: even saying to Jerusalem, Thou shalt be built; and to the temple, Thy foundation shall be laid. 
(Isaiah 44:1-28)
Thus saith the LORD to his anointed, to Cyrus, whose right hand I have holden, to subdue nations before him; and I will loose the loins of kings, to open before him the two leaved gates; and the gates shall not be shut; 
(Isaiah 45:1)
I have made the earth, and created man upon it: I, even my hands, have stretched out the heavens, and all their host have I commanded. I have raised him up in righteousness, and I will direct all his ways: he shall build my city, and he shall let go my captives, not for price nor reward, saith the LORD of hosts. 
(Isaiah 45:12-13)
For Jacob my servant's sake, and Israel mine elect, I have even called thee by thy name: I have surnamed thee, though thou hast not known me. I am the LORD, and there is none else, there is no God beside me: I girded thee, though thou hast not known me: 
(Isaiah 45:4-5)
Jeremiah told the people how long it would be before God would free them from the Babylonian captivity: 
For thus saith the LORD, That after seventy years be accomplished at Babylon I will visit you, and perform my good word toward you, in causing you to return to this place. 
(Jeremiah 29:10)
Was this real prophecy?
Can God see into the future? 
God made the future. 
God is the future. 
Some one hundred years after God's message to Isaiah, we read the following historical report: 
And they burnt the house of God, and brake down the wall of Jerusalem, and burnt all the palaces thereof with fire, and destroyed all the goodly vessels thereof. And them that had escaped from the sword carried he away to Babylon; where they were servants to him and his sons until the reign of the kingdom of Persia: To fulfil the word of the LORD by the mouth of Jeremiah, until the land had enjoyed her sabbaths: for as long as she lay desolate she kept sabbath, to fulfil threescore and ten years. Now in the first year of Cyrus king of Persia, that the word of the LORD spoken by the mouth of Jeremiah might be accomplished, the LORD stirred up the spirit of Cyrus king of Persia, that he made a proclamation throughout all his kingdom, and put it also in writing, saying, Thus saith Cyrus king of Persia, All the kingdoms of the earth hath the LORD God of heaven given me; and he hath charged me to build him an house in Jerusalem, which is in Judah. Who is there among you of all his people? The LORD his God be with him, and let him go up. 
(2 Chronicles 36:19-23)
Despite the warnings given by God to His people through Isaiah, Jeremiah et al, they were defeated and taken to Babylon. Jeremiah told them that they would be there seventy years and we see that king Cyrus did exactly as Isaiah prophesied. 
This shows that the Bible is a prophetic book as it reveals the Truth. 
Moreover, this is God's word to us to take note of and obey, if we love Him. 
I love God for His love for me. 
I love my Lord Jesus Christ for His love for His Heavenly Father and His love for me. 
I believe His word.
I believe that I shall one day be in the Heavenly Presence. 
In amongst the prophecy about King Cyrus is a gem; a Truth of what it is all about. A parallel between the old and new Covenants. 
In the old Covenant the nation of Israel was in Covenant with Jehovah. They were the chosen nation because of that Covenant. But only those of them who each returned to God from their evil ways would be redeemed. 
Remember these, O Jacob and Israel; for thou art my servant: I have formed thee; thou art my servant: O Israel, thou shalt not be forgotten of me. I have blotted out, as a thick cloud, thy transgressions, and, as a cloud, thy sins: return unto me; for I have redeemed thee. 
(Isaiah 44:21-22)
Look unto me, and be ye saved, all the ends of the earth: for I am God, and there is none else. 
(Isaiah 45:22)
In the new Covenant that Jesus Christ made on our behalf with Father God, the message is the same. Confess that God raised the Lord Jesus from the dead and we each become part of the Christian "nation"; if we each believe unto righteousness and obedience. 
But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. For the scripture saith, Whosoever believeth on him shall not be ashamed. 
(Romans 10:8-11)
And it came to pass the day after, that he went into a city called Nain; and many of his disciples went with him, and much people. Now when he came nigh to the gate of the city, behold, there was a dead man carried out, the only son of his mother, and she was a widow: and much people of the city was with her. And when the Lord saw her, he had compassion on her, and said unto her, Weep not. And he came and touched the bier: and they that bare him stood still. And he said, Young man, I say unto thee, Arise. And he that was dead sat up, and began to speak. And he delivered him to his mother. And there came a fear on all: and they glorified God, saying, That a great prophet is risen up among us; and, That God hath visited his people. 
(Luke 7:11-16)
Then came to him his mother and his brethren, and could not come at him for the press. And it was told him by certain which said, Thy mother and thy brethren stand without, desiring to see thee. And he answered and said unto them, My mother and my brethren are these which hear the word of God, and do it. 
(Luke 8:19-21)
Remember the former things of old: for I am God, and there is none else; I am God, and there is none like me, Declaring the end from the beginning, and from ancient times the things that are not yet done, saying, My counsel shall stand, and I will do all my pleasure: 
(Isaiah 46:9-10) 
Who is among you that feareth the LORD, that obeyeth the voice of his servant, that walketh in darkness, and hath no light? let him trust in the name of the LORD, and stay upon his God. 
(Isaiah 50:10)