Just because someone professes to be a Christian, he is not necessarily truly a Christian.  Jesus spoke of people who called him "Lord" and who did all kinds of wonderful works.  But he will cast them away from his presence at the judgment and call them "workers of iniquity," because he never knew them (Matt. 7:22-23).  John writes about people who were a part of the Christian assembly and then left.  He said that their leaving indicated they never really belonged (1 John 2:19).  These examples suggest to us that, conversely,  those whom Jesus truly knows, and who know Him, and those who truly belong to the company of the saved will be saved.

Using the figure of sheep and shepherd, Jesus taught that his sheep know Him and that He knows His sheep (John 10:14, 27).  He goes on to say that He, as the Good Shepherd, lays down his life for the sheep (John 10:15), that He gives them eternal, not temporary, life, that they will never perish, and that no one can snatch them out of His hand (John 10:28).  He continues in the next verse by saying that no one can snatch them out of His Father's hand.  The idea is that the sheep are doubly enclosed in both the hand of the Son and in the hand of the Father.  Nothing could make them more secure.

Earlier in the Bread of Life Sermon, Jesus told his audience that He had come from heaven, not to do his own will, but the will of the Father who sent Him, and that this will of the Father was that he should lose none of all the Father gave Him, but raise them up at the last day (John 6:38-39).  In His great High Priestly prayer, Jesus prayed that the Father would glorify Him on the basis of the fact that the Father had granted him authority over all flesh in order that Jesus might give eternal life to all those the Father had given Him.  And this eternal life consists in knowing the Father and the Son (John 17:2-3).  The language of Jesus suggests to us that the salvation of all those the Father has given to Him is His assigned work, and the loss of one soul would mean that the Son failed in that task.  Such an idea is unthinkable and leads us to the conclusion that none of those who are brought into a truly saved relationship with God through Christ, a relationship of knowing the Father and the Son, shall be lost.

The apostle Paul is just as adamant when he presents the gospel to his readers.  In Romans 8:29-30 he states plainly that those the Father has called and justified are, in the sight of God, already glorified.  At the end of the chapter he asserts that nothing in all creation can separate us from the love of God in Christ (Rom. 8:37-39).  Earlier he taught forcefully that if we are justified by the blood of Christ, how much more shall we be saved from wrath, and if we were reconciled while yet an enemy of God, how much more shall we be saved through His life (Rom. 5:9-10).  Paul told the Philippians that He who began a good work in us will bring it to completion until the day of Christ (Phil. 1:6), and he wrote to the Thessalonians that the God who called us is faithful, and he will sanctify us completely and keep our whole spirit, soul and body blameless (1 Thess. 5:23-24). 

Salvation is the work of God, the Triune God, and not of man.  If you are truly a believer in Christ, you may be absolutely sure of your salvation.  You cannot lose it because you never earned it; it was a gift (Eph. 2:8).  You have the firm promise of the Father (Heb. 6:17-20), the ongoing intercession of the Son (Heb. 7:25, Rom. 8:34), and the seal of the Holy Spirit (Eph. 1:13-14) to rest your assurance upon.

For more information on this subject you may request our tape series "Doctrines of Grace" and "Justification by Faith."