Do you think that a person would go to the lake of fire for killing himself? It is murder, but at the same time God knows where the person's heart is at the time.
Sadly, some people get so despondent that they conclude that taking their own lives would be a relief. Of course, there are many reasons a person may come to the decision to commit suicide—none of which would be justified in the eyes of God. God says that murdering a human being is a sin, even if it is taking one's own life (Exodus 20:13).
It is true that many people (and young people in particular) who make such decisions are consumed with loneliness, despair and rejection. Some are suffering from mental health problems that can add to the emotional burdens they are bearing. In many cases, they perceive they are trapped in their circumstances and simply cannot change them or "get out."
We live in a world that is ruled by Satan the devil (2 Corinthians 4:4; Ephesians 2:2). He influences the attitudes and actions of all that he can. His goal is to supplant God's great plan of salvation. He will do so any way he can. If Satan cannot get people to destroy each other, he will encourage them to destroy themselves. Satan takes advantage of the limitations of the human mind and attitudes that we have. So, a person in a seemingly hopeless and despondent state can be affected by the influence of Satan to consider alternatives (such as taking one's life) that God would never approve of.
Yet God is a God of mercy. If people make such a horrible and needless mistake, God can forgive them, but only after the resurrection and their realization that taking their own life was a needless and wrong thing to have done.
God's desire is for us to change, to overcome, and realize the benefits of living His way. That may seem very tough sometimes in a world that is going the opposite direction. However, it is possible, and God promises us we will reap what we sow. If we are striving to serve God and live His way of life, God will bless us in so many ways. God's Word and His plan can give us many reasons to live. God's way ultimately gives us the hope of the future that should make us want to live. God wants us to deeply respect and appreciate the sanctity of life—since He is the giver of life itself and human life is a precursor of eternal life.
As for what happens after one dies, there are many opinions but only one biblical answer. The Bible says those who die go to their graves until they are resurrected (John 5:28, 29; 1 Corinthians 15:52; 1 Thessalonians 4:16). If you would like to learn more about this subject, we recommend you read our free booklet, Heaven & Hell: What Does the Bible Really Teach?