A commonly asked question is whether a born-again believer who commits suicide will still go to heaven. The answer to this and other related questions depends on the biblical data and one's view of God's grace.
The Bible teaches that human life is sacred. Suicide is the taking of a life that is uniquely created, made in God's image, and given as a gift. The commandment "You shall not murder" does not specify an object and can include oneself as well as others. In principle then, suicide is equal to murder; it could be called self-murder. (Giving one's life to help another would not be suicide - it is considered the ultimate act of love. John 15:13)
For the Christian, suicide is also the taking of a life that does not belong to him or her:
This passage has the Christian's physical body in view, as indicated by the surrounding context which discusses sexual immorality and the body.
Some think that 1 Corinthians 3:16-17 teaches that suicide is punished with eternal destruction.
Some would say that a person who claims to be a Christian and commits suicide just proves that he or she was never really a Christian at all. But there is no evidence in the Bible that those who have believed possess anything less than eternal life, which by definition cannot be lost. This view often assumes that all Christians persevere in faithfulness and obedience until the end of their life, but biblical evidence disproves that (e.g. Acts 5:1-11; 1 Cor. 11:30).
The Bible shows that believers are capable of terrible sins, even murder (e.g. King David). Believers can abuse the grace of God. Suicide, though terrible, is another sin that a believer can commit. According to the Bible, all of the believer's sins are forgiven (Col. 2:13). That is why there is no condemnation to those who are in Christ (Rom. 8:1) and nothing can separate a believer from the love of Christ, even death - death from whatever cause (Rom. 8:35-39).
The Bible promises that "If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness" (1 John 1:9). But a believer who commits suicide cannot confess that sin. Yet the truth is every believer will probably die with some specific sins not confessed. Besides, 1 John 1:9 relates to the believer's fellowship and walk with God, not the condition for obtaining eternal salvation (cf. 1:3, 6-7). Confessing each and every sin is not a condition of eternal salvation. The only condition is faith in Christ and His offer of eternal life based on His finished work of paying for our sins on the cross. Christians can be assured that when they sin, they have an Advocate with the Father, Jesus Christ, who satisfies God's justice for all of our sins (1 John 2:1-2).
Since God is omniscient and by His grace forgives all sins, past, present, and future, there is no sin that will surprise God or make Him regret having saved someone. The Bible also teaches that where sin abounds, grace abounds much more (Rom. 5:20). No one can out-sin God's grace! Knowing this, a Christian should never presume upon God's grace by committing any sin, much less suicide. Suicide is a selfish and serious sin that dishonors God, hurts other people, and deprives God of one's service on earth. Any abuse of God's grace has its consequences - a qualitative loss in this life and in the eternal experience as well. But that loss is in the quality of one's fellowship or enjoyment of God, not in one's relationship to God.
A realistic view of humanity admits that Christians can sin severely, even to the point of committing suicide. But a realistic view of the Bible admits that God's grace is great enough to cover even the worst of sins. Suicide is a grievous and tragic sin, but Jesus died for such sins. This is by no means an encouragement to sin or commit suicide; rather it is another motivation to worship and serve a God who is so gracious.