Why Did Jesus Come? 
To preach the Kingdom of heaven:
And he said unto them, I must preach the kingdom of God to other cities also: for therefore am I sent. 
(Luke 4:43)
And Jesus answering said unto them, They that are whole need not a physician; but they that are sick. I came not to call the righteous, but sinners to repentance. 
(Luke 5:31-32)
Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you. 
(Luke 17:21)
To become the Covenant Sacrifice of the New Testament. 
See "Heart of the Gospel".
Jesus also fulfilled many prophesies concerning the coming of the Messiah. 
A well known Bible Expositor had this to say: 
It is beyond our comprehension, but inescapably true, that from all eternity Christ looked forward to the Cross, which He would one day endure "for the joy that was set before him" (Heb 12:2). Significantly, the book that decides the fate of the damned is called the book of life "of the Lamb slain from the foundation of the world" (Rev 13:8). In the unthinkable but inevitable horror of man's murder of God's Son, the real face of evil was unmasked, the true heart of man - "deceitful above all things, and desperately wicked" (Jer 17:9) - was laid bare, and God's eternal justice and love were demonstrated beyond dispute for all eternity to ponder. In the crime of all ages, man despised, rejected, humiliated, scourged, and nailed his Creator to a cross. Thus the rebellion of self hidden in the human heart - the raw passion to tear God from His throne if possible - was revealed, and God's loving response silenced all legitimate complaint. 
When mankind, incredibly, was venting its full hatred upon its Creator, God responded in love and forgiveness, submitting not only to the unjust treatment man imposed but also to the punishment of infinite justice against the sins of the world, interceding even for those who mocked and crucified Him: "Father, forgive them. . .they know not what they do" (Lk 23:24). Only by the full payment being made to satisfy God's justice could God "be just, and the justifier of him which believeth in Jesus" (Rom 3:26). We cannot doubt God's wisdom, nor can we fault His love. Therefore, we know that this is the way it had to be. . . . 
We can't imagine what it really means that the Son always knew that He would be born into this world as a babe, would live a perfect, sinless life as only He could, be hated without cause, be rejected and despised by His own people, the Jews, to whom He would come as one of them, and that they, with the willing co-operation of the Roman Empire, would crucify Him. Of course, the truth of our redemption goes far beyond our capacity to comprehend. We are told that "by his knowledge shall my righteous servant justify many" (Isa 53:11). That seems a cryptic statement. 
What could knowledge have to do with paying the penalty for our sins? Obviously, without full knowledge of every detail (including motivation) of every shameful, violent, appalling sin that would ever be committed from all eternity - without full knowledge of the penalty His own justice required - God's "righteous servant" could not pay the full debt that mankind owed for its wickedness and thereby "justify" all who would believe on Him. Indeed, He would be punished as though He were sin itself: " for he [God] hath made him [Christ] to be sin for us, [he] who knew no sin; that we might be made the righteousness of God in him" (2Cor 5:21). What love, what mercy, what grace! 
Christ's triumphant cry on the cross, "It is finished!" takes on greater significance when we understand that He had eternally anticipated that moment: "this man [Christ], after he had offered one sacrifice for sins forever, sat down on the right hand of God. . .for by one offering he hath perfected forever them that are sanctified. . . .Now. . .there is no more offering for sin" (Heb 10:12,14,18). At last it was all behind Him - the penalty paid once-for-all and in full for all mankind. 
Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels? But how then shall the scriptures be fulfilled, that thus it must be? 
(Matthew 26:53-54)
What does Jesus expect of us?
For ever, O LORD, thy word is settled in heaven. Thy faithfulness is unto all generations: thou hast established the earth, and it abideth. They continue this day according to thine ordinances: for all are thy servants. Unless thy law had been my delights, I should then have perished in mine affliction. I will never forget thy precepts: for with them thou hast quickened me. I am thine, save me; for I have sought thy precepts. The wicked have waited for me to destroy me: but I will consider thy testimonies. I have seen an end of all perfection: but thy commandment is exceeding broad. MEM. O how love I thy law! it is my meditation all the day. Thou through thy commandments hast made me wiser than mine enemies: for they are ever with me. I have more understanding than all my teachers: for thy testimonies are my meditation. I understand more than the ancients, because I keep thy precepts. I have refrained my feet from every evil way, that I might keep thy word. I have not departed from thy judgments: for thou hast taught me. How sweet are thy words unto my taste! yea, sweeter than honey to my mouth! Through thy precepts I get understanding: therefore I hate every false way. Thy word is a lamp unto my feet, and a light unto my path. I have sworn, and I will perform it, that I will keep thy righteous judgments. I am afflicted very much: quicken me, O LORD, according unto thy word. Accept, I beseech thee, the freewill offerings of my mouth, O LORD, and teach me thy judgments. My soul is continually in my hand: yet do I not forget thy law. The wicked have laid a snare for me: yet I erred not from thy precepts. Thy testimonies have I taken as an heritage for ever: for they are the rejoicing of my heart. I have inclined mine heart to perform thy statutes alway, even unto the end. SAMECH. I hate vain thoughts: but thy law do I love. Thou art my hiding place and my shield: I hope in thy word. Depart from me, ye evildoers: for I will keep the commandments of my God. Uphold me according unto thy word, that I may live: and let me not be ashamed of my hope. Hold thou me up, and I shall be safe: and I will have respect unto thy statutes continually. Thou hast trodden down all them that err from thy statutes: for their deceit is falsehood. Thou puttest away all the wicked of the earth like dross: therefore I love thy testimonies. 
(Psalms 119:89-119)
Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth. But shun profane and vain babblings: for they will increase unto more ungodliness. 
(2 Timothy 2:15-16)
But speak thou the things which become sound doctrine: That the aged men be sober, grave, temperate, sound in faith, in charity, in patience. The aged women likewise, that they be in behaviour as becometh holiness, not false accusers, not given to much wine, teachers of good things; That they may teach the young women to be sober, to love their husbands, to love their children, To be discreet, chaste, keepers at home, good, obedient to their own husbands, that the word of God be not blasphemed. Young men likewise exhort to be sober minded. In all things shewing thyself a pattern of good works: in doctrine shewing uncorruptness, gravity, sincerity, Sound speech, that cannot be condemned; that he that is of the contrary part may be ashamed, having no evil thing to say of you. Exhort servants to be obedient unto their own masters, and to please them well in all things; not answering again; Not purloining, but shewing all good fidelity; that they may adorn the doctrine of God our Saviour in all things. For the grace of God that bringeth salvation hath appeared to all men, Teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world; Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ; Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works. These things speak, and exhort, and rebuke with all authority. Let no man despise thee. 
(Titus 2:1-15)
Next time, Jesus will return in Power.