The problem is the idea that salvation is lost if someone commits suicide is very fragile.
Let us say a person had salvation prior to committing suicide. They are born again, elect, called, justified, forgiven, and adopted by God through the sacrifice of Christ for their sins. They fall into depression and desperation due to some inner or outward crisis. It could even be a chemical imbalance. In this confused and emotional state they take their own life and because they could not confess this sin after they did, then the are no longer born again, elect, called, justified, forgiven, or adopted. One sin not confessed before death damns them to hell and makes them God’s orphaned and abandoned children. This is hard to reconcile with the biblical idea of salvation.

Our options here are

1. Suicide always indicates that the person was not a true believer and therefore never saved. Since suicide is a form of murder this would mean that this would be one of the sins that the person would be judged for but not be the reason why a person would be damned to hell. They are lost because they never accepted the payment for their sins in Jesus Christ.

2. Suicide is an unforgivable sin not covered by the blood of Christ. It is the blasphemy of the Holy Spirit the only unforgivable sin. It is the greatest sin of all sins.

3. Suicide damns a person to hell because they cannot confess and repent of it. Now this would mean that if a person committed any sins right before their death they would be damned as well. Let us say that we had impure thought just before we died, then this would damn us to hell. Say we became angry and died that would send us to hell. This however means that we have to totally confessed up as we take our last breath and that would make our salvation very fragile. This is the idea of “last rites” in the Roman Catholic tradition.

4. Suicide is a serious sin when it is done by a person not suffering from a biological imbalance in which they are not able to make rational choices.

Suicide may in some cases indicate a lack of faith in Jesus Christ as Lord and Savior and if this is the case such a person is damned to a just punishment in hell not only because they committed suicide but for all their sins which were nor forgiven by the substitution of Christ’s suffering.

Suicide may in some cases be committed by people who have true faith in Christ as a dark and desperate moment in which they act in unbelief. Christians are not sinless. They remain wounded, weak, wicked, and wild even as they are being wonderfully transformed by God’s power one step at a time towards becoming like Christ. We are saved not because we have avoided a particular sin but because Christ has paid for our sins. Our faith and repentance are how we receive Christ and are the the basis of our justification with God. Christ’s sacrifice and life are our righteousness before God alone. The sin of suicide cannot separate us from the love of God that is in Christ Jesus.

One of the fruits of faith is an attitude of continual confession. Our confession is never perfect but it expresses our faith in Christ. This is the framework that 1 John 1:8,9 should be understood in and not that one not confessed sin before death would damn a person to hell. If this is the case we have a lot more to be worried about than merely suicide.

Paul murdered Christian and this can be forgiven. Taking another person’s life is even more serious than taking our own life. Causing other people harm is more immoral than causing ourselves harm. If causing other people harm can be forgiven but suicide cannot then this would seem unfair.
The key is that Ephesians 1 tells us that God predestined people to be HIS children for all eternity. Our salvation did not begin with us but with God. God does not lose any his redeemed children.
And we know that for those who love God all things work together for good, for those who are called according to his purpose. For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified.
(Rom 8:28-30)

So 100% of those who God predestined, God called to faith in Jesus Christ, and 100% of those called to have faith in Jesus Christ he justified (declared righteous and pardoned) and 100% of those God justified by grace alone are also glorified in the kingdom of heaven.
Suicide cannot break the golden chain of salvation unless the person was never saved at all. Not predestined, called, or justified. In such a case they would be condemned and not glorified but not only because of suicide.

This is especially important to understand in comforting people who have lost loved ones due to suicide. Clearly we can warn a person thinking of suicide that this may mean they don’t really have faith in Christ and that they could be facing eternal damnation. But even here we need to keep the focus on true faith and empty false profession.

So in conclusion, no sin that is not confessed prior to death including suicide can be the sole and only reason a person is damned to just punishment in hell. If a person does not really and sincerely trust in Jesus Christ as their personal Lord and Savior then they will be judged justly for their sins when they die and this would include their suicide. But they would be justly judged in hell for all their sins and not just their suicide.

If a person was chosen by God to believe in Jesus Christ as their Lord and Savior from all eternity so that their sins would be paid for by Christ’ sacrifice on the cross then any sin the true Christian commits prior to death cannot separate them from God’s eternal redemptive love and plan, and this includes the sin of suicide.

Only if suicide expresses a lack of faith in Jesus as Lord and Savior does it become part of the reason a person is lost.

Also any suicide that is done while a person is in an irrational state of mind or biologically unable to make rational decisions is not a moral issue. This is not a sin. It is part of the sad reality of living East of Eden. So this action would not be part of any punishment in hell or a reason to be lost.