What happens when a believer commits suicide? Will he lose his salvation?

A person who has truly believed in and accepted the Lord Jesus Christ is assured of salvation and eternal life. However, there are believers who, when faced with trials and testing, may choose compromise over faithfulness—even to the point of cutting their lives short. In such cases, what is forfeited is not their salvation, but the rewards—the crowns—that the Lord desires to give them one day as a recognition of their faithfulness. It is a sobering reminder that while eternal life is a gift of grace, our faithfulness in overcoming trials and testings in our lives determines the eternal rewards (eg. crown of life) we receive. I believe that such a person will still be accountable to God for the decision to cut their life short, as life is a sacred gift entrusted to us by Him. This person has no grasp of the unimaginable joy and glory that awaits those who love the Lord Jesus Christ with all their heart, soul, mind, and strength. The eternal reward prepared for those who remain faithful is beyond anything this world can offer or comprehend. Blessed is the man who remains steadfast under trial, for when he has stood the test he will receive the crown of life, which God has promised to those who love him. - James 1:12 So then each of us will give an account of himself to God. - Romans 14:12 But as Scripture says: “No eye has seen, no ear has heard, and no mind has imagined the things that God has prepared for those who love him.” God has revealed those things to us by his Spirit. The Spirit searches everything, especially the deep things of God. - 1 Corinthians 2:9-10