The Truth of the Spirit 
And ye shall know the truth, and the truth shall make you free. 
(John 8:32)
There are some in your circle of Christian acquaintances who say "all you have to do is believe and you shall be saved" quoting Romans 10:8-10, not so. 
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. 
(Romans 10:8-10)
They understand that by believing Jesus Christ is Lord and that God raised Him from the dead, they shall be saved. The word saved implies that this is a permanent state, like being saved from a shipwreck. 
Many famous preachers and teachers promote this belief and have Scriptures to show, which seem to prove that they are right. 
We know that the Bible contradicts this and must ask ourselves how can there be contradictions in God's word. 
It can only be that we do not understand what God means. 
After many years puzzling over this question, I would like to intimate that it has been revealed that the crux lies in the phrase "believeth unto righteousness". 
Just as the word "baptise" was an unfortunate choice used by the Bible translators, as it should have promoted a clearer meaning as to the purpose of the immersion; so the word "believe" should be more closely associated with "believeth unto righteousness". In other words, our faith is of such a nature and is so real that we have changed our ways and attempt to live righteously. Being "saved" not only means that our names are now entered into a book of life, but that we are empowered by the Holy Spirit. We are converted (switched) from evil (worldly) ways to righteous (Godly) ways because we were first convicted in our hearts to do so. We now see everything and every person in a changed light. We each become increasingly aware of the spiritual nature of the world around us and our lives and circumstances. In this way we become a follower, a disciple of our Lord. Jesus Christ is truly Lord. He is our loving Master. 
When one is convicted of a crime by a judge as a result of his designated power, one becomes a convict in a jail because of crimes that were committed against the laws of the land. The period in jail serves to "wipe the slate clean". The price has been paid. 
When we are convicted by our conscience (spirit/soul) of previous sins committed, wishing to have them repudiated, we need to admit (confess) them, to "get them off our chest". God is our Judge; and if we come to Him believing that Jesus has the power to be our Advocate to plead our case, using His own blood as the cleansing medium in total defence, He will prove to the Great Judge that the sentence has already been carried out. The price has been paid. 
When crouched at the feet of Christ Jesus, crying out in repentance, it is because we have been convicted in our hearts of our sins. 
We have at last understood that Jesus, who is part of the Godhead, actually died for us. God so loves me that He died on my behalf, a dirty rotten sinner who will never be able to properly reciprocate that love. We have to respond in love, we cannot help ourselves. In that broken state of helplessness God really shows His love by coming to live inside each of us, to guide and strengthen us spiritually. 
And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God. 
(1 Corinthians 6:11)
What did Isaiah say?
Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, the LORD of hosts. Then flew one of the seraphims unto me, having a live coal in his hand, which he had taken with the tongs from off the altar: And he laid it upon my mouth, and said, Lo, this hath touched thy lips; and thine iniquity is taken away, and thy sin purged. Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me. 
(Isaiah 6:5-8)
We have willingly admitted our breaking of the law of God to Him in the past. We ask to be forgiven because we have seen the evil of our ways, we throw ourselves at the mercy of the Great Judge; we become His servant, His prisoner. 
Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God, 
(Romans 1:1)
For this cause I Paul, the prisoner of Jesus Christ for you Gentiles, 
(Ephesians 3:1)
In response to the admission of our own helplessness, of the lack of power to save ourselves, God, in His lovingkindness, enters into us in the Person of the Holy Spirit and guides and strengthens us: and because we each now belong to Him we are under His protection, both spiritually and physically. 
What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's. 
(1 Corinthians 6:19-20)
Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world.
(1 John 4:4)
However, we need to spend time every day to come into God's loving, peaceful presence, to listen for His voice and to be guided by His truth and wisdom. To learn more of Him. 
In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, 
(Ephesians 1:13)
He therefore that despiseth, despiseth not man, but God, who hath also given unto us his holy Spirit. 
(1 Thessalonians 4:8)
Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost; 
(Titus 3:5)
Once we become too busy, like the grains of wheat among thorns described in Matthew 13:22, we can quench, or put out the fire of the Holy Spirit. 
Now we exhort you, brethren, warn them that are unruly, comfort the feebleminded, support the weak, be patient toward all men. See that none render evil for evil unto any man; but ever follow that which is good, both among yourselves, and to all men. Rejoice evermore. Pray without ceasing. In every thing give thanks: for this is the will of God in Christ Jesus concerning you. Quench not the Spirit. 
(1 Thessalonians 5:14-19)
God is always faithful and He governs in love because He is love, and will always honour His commitment to each one of us. The weakness is always on our side. 
So, we have to overcome the wiles of the evil one, the god of this world; and as we shall see in another writing1 this is not easy. 
However, by asking for wisdom and obeying the will of our Master we overcome the power of Satan: 
Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world. They are of the world: therefore speak they of the world, and the world heareth them. We are of God: he that knoweth God heareth us; he that is not of God heareth not us. Hereby know we the spirit of truth, and the spirit of error. 
(1 John 4:4-6)
Here are a few examples of what God says in His word: 
And Solomon stood before the altar of the LORD in the presence of all the congregation of Israel, and spread forth his hands toward heaven: And he said, LORD God of Israel, there is no God like thee, in heaven above, or on earth beneath, who keepest covenant and mercy with thy servants that walk before thee with all their heart: 
(1 Kings 8:22-23)
Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord; 
(Acts 3:19)
Unto you first God, having raised up his Son Jesus, sent him to bless you, in turning away every one of you from his iniquities. 
(Acts 3:26)
What then? shall we sin, because we are not under the law, but under grace? God forbid. Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness? But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you. Being then made free from sin, ye became the servants of righteousness. 
(Romans 6:15-18)
Till I come, give attendance to reading, to exhortation, to doctrine. Neglect not the gift that is in thee, which was given thee by prophecy, with the laying on of the hands of the presbytery. Meditate upon these things; give thyself wholly to them; that thy profiting may appear to all. Take heed unto thyself, and unto the doctrine; continue in them: for in doing this thou shalt both save thyself, and them that hear thee. 
(1 Timothy 4:13-16)
Please also read Ephesians chapter two.
It is obvious that God does not say that we cannot lose our salvation. Romans chapter ten must therefore mean that at the time of our conversion we have moved into the household of God and are therefore saved. But what about tomorrow? Have we moved house? 
We need to carry on "believing", to live as Jesus would like us to, to keep in God's "good books". 
Here is a prayer of king Solomon the wise:
And hearken thou to the supplication of thy servant, and of thy people Israel, when they shall pray toward this place: and hear thou in heaven thy dwelling place: and when thou hearest, forgive. If any man trespass against his neighbour, and an oath be laid upon him to cause him to swear, and the oath come before thine altar in this house: Then hear thou in heaven, and do, and judge thy servants, condemning the wicked, to bring his way upon his head; and justifying the righteous, to give him according to his righteousness. When thy people Israel be smitten down before the enemy, because they have sinned against thee, and shall turn again to thee, and confess thy name, and pray, and make supplication unto thee in this house: Then hear thou in heaven, and forgive the sin of thy people Israel, and bring them again unto the land which thou gavest unto their fathers. When heaven is shut up, and there is no rain, because they have sinned against thee; if they pray toward this place, and confess thy name, and turn from their sin, when thou afflictest them: Then hear thou in heaven, and forgive the sin of thy servants, and of thy people Israel, that thou teach them the good way wherein they should walk, and give rain upon thy land, which thou hast given to thy people for an inheritance. If there be in the land famine, if there be pestilence, blasting, mildew, locust, or if there be caterpiller; if their enemy besiege them in the land of their cities; whatsoever plague, whatsoever sickness there be; What prayer and supplication soever be made by any man, or by all thy people Israel, which shall know every man the plague of his own heart, and spread forth his hands toward this house: Then hear thou in heaven thy dwelling place, and forgive, and do, and give to every man according to his ways, whose heart thou knowest; (for thou, even thou only, knowest the hearts of all the children of men;) That they may fear thee all the days that they live in the land which thou gavest unto our fathers. 
(1 Kings 8:30-40)
If they sin against thee, (for there is no man that sinneth not,) and thou be angry with them, and deliver them to the enemy, so that they carry them away captives unto the land of the enemy, far or near; Yet if they shall bethink themselves in the land whither they were carried captives, and repent, and make supplication unto thee in the land of them that carried them captives, saying, We have sinned, and have done perversely, we have committed wickedness; And so return unto thee with all their heart, and with all their soul, in the land of their enemies, which led them away captive, and pray unto thee toward their land, which thou gavest unto their fathers, the city which thou hast chosen, and the house which I have built for thy name: Then hear thou their prayer and their supplication in heaven thy dwelling place, and maintain their cause, And forgive thy people that have sinned against thee, and all their transgressions wherein they have transgressed against thee, and give them compassion before them who carried them captive, that they may have compassion on them: For they be thy people, and thine inheritance, which thou broughtest forth out of Egypt, from the midst of the furnace of iron: That thine eyes may be open unto the supplication of thy servant, and unto the supplication of thy people Israel, to hearken unto them in all that they call for unto thee. For thou didst separate them from among all the people of the earth, to be thine inheritance, as thou spakest by the hand of Moses thy servant, when thou broughtest our fathers out of Egypt, O Lord GOD. And it was so, that when Solomon had made an end of praying all this prayer and supplication unto the LORD, he arose from before the altar of the LORD, from kneeling on his knees with his hands spread up to heaven. And he stood, and blessed all the congregation of Israel with a loud voice . . . 
(1 Kings 8:46-55)
When we each come into Covenant with God through the saving power of the Lord Jesus Christ we are in a similar position to the Children of Israel who came before God under the mountain and made a Covenant as a nation. The Old Covenant can therefore be used as a guideline to understand what is in store for us. 
It would seem then that all believers into God who have their names still entered in one of the books of life at the time of their physical deaths shall be given a chance to stand on that day and declare themselves, either confirming that their names are already in the Lamb's Book of Life or having the opportunity at this time of convincing God that their names should be entered there2. See also 1 Corinthians 5:5. 
Those who have had their names removed from any of the books shall not have this opportunity. See also Revelation 3:5. 
Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour. 
(1 Corinthians 3:8)
Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you? If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are. 
(1 Corinthians 3:16-17)
So, in future, when you should come upon someone who raises the "only believe" story, you can show him or her what God actually means what He says. 
1 God is Love.
2 See God our Saviour.