I know the Church is unconditionally saved and we are the only group to be so blessed. This means that if a true believer during the church age committed suicide they would still be saved, albeit lose all their rewards. What about the believer during the tribulation who may be so despaired that they commit suicide. Would they still be saved?
Interesting question. As you say, the Church alone has eternal security with all our sins past, present, and future forgiven. And being a violation of the commandment against murder (Exodus 20:13), suicide is a sin. It all comes down to whether a post rapture believer contemplating suicide can pray, “Lord forgive me for what I’m about to do.” (In the Old Covenant forgiveness was for past sins only.)
Rev. 9:6 says, “During those days people will seek death but will not find it; they will long to die, but death will elude them.” Maybe suicide won’t be an option.