When someone takes their own life for various reasons, do they have a chance to go to heaven if they have always believed in Jesus Christ?
A significant phrase in your question is “for various reasons.” People have taken their lives for various reasons. Some who did so might have been suffering from psychological or mental health issues. Others might have committed a rash act in a moment of weakness. Still others might have ended their lives in unbelief.
The Bible teaches us that Christian faith saves and unbelief condemns (Mark 16:16). The Bible explains the need to have Christian faith in the heart when life on earth comes to an end (Revelation 2:10). The Bible informs us that judgment takes place at death (Hebrews 9:27). While we do not know the judgment that takes place at a person’s death, that judgment will be made public on the last day (Matthew 25:31-46).
In years past, individuals who took their own lives were often treated as a group: they were automatically considered to be people who were lost forever. In more recent times there has been a greater understanding of psychological and mental issues that might have contributed to a person taking his or her life, while still dying in the Christian faith. This does not minimize the seriousness of suicide or its tragic effects on survivors; it provides explanation only.
God makes it clear in the Bible that only he—directly or indirectly through his representatives in government—has the right to end a person’s life (Deuteronomy 32:39; Psalm 31:15; Psalm 90:3; Romans 13:4). God is serious about protecting a person’s life because that is the only time a person has to be brought to saving faith in Jesus Christ.
Any threat or expression of ending one’s life needs to be taken very seriously. If you are aware of such threats or expressions, do speak to that person and/or the proper authorities.