Question: I have heard many times that suicide is the unpardonable sin. Does the Bible really say that?
Answer: I have heard the same for years. This claim, which is erroneous, comes from those who say "the Bible says," when they have no idea what the Bible says! The only "unpardonable sin" is the sin of unbelief. If you die without trusting Christ as Savior, your destiny is sealed in Hell.
Since I was a boy, I have heard that "Cleanliness is next to Godliness," and that it was in the Bible. I have not found that text to this day! May I suggest that you always ask for "chapter and verse" to substantiate someone's claim. The standard answer is, "I know I have read it, but I can’t remember where." Tell them to go home and find it!
There are two references usually cited as regarding the "Unpardonable Sin." Matthew 12:31,32, "blasphemy against the Holy Spirit" and 1 John 5:16, "There is a sin unto death." The Matthew text has nothing to do with suicide; but is a dispensational sin of Israel in rejecting Christ as their Messiah.
In 1 John 5:16 the last part of the verse says,
"There is a sin unto death. I do not say that he shall pray for it."
In the original this would read, "There is sin unto death," as there is no Greek or Hebrew word for the article "a." This has nothing to do with suicide, but means that you should not pray for someone after they have died. As we said, their destiny is sealed, they are in Heaven or Hell depending on the decision they made while they were still living.
Usually, suicide is the result of concluding there is no way out of a situation and life must be hopeless. This can happen to a believer as well as an unbeliever. Does a Christian lose their salvation if they commit suicide? Absolutely not, as this would make God a liar when He promised EVERLASTING LIFE! Yes, suicide is a sin; but, Christ forgave all sin, including taking one’s own life. Remember, before Paul’s conversion he killed many Christians, yet God forgave him—taking a murderer and making him into a missionary.