It doesn't. That's a Catholic tradition, not a Biblical teaching.
Maybe a Roman Catholic interpretation, you mean? I am not sure what most Protestant denominations officially think about this matter, and having no church myself right now I don't know what my denomination thinks either since I don't have one.
But, after looking it up on google, I found an article which compares six Christian denominations and the views that they have on various topics. For the topic of suicide, Roman Catholics, Eastern Orthodox, Lutherans, and Methodist/Weslyan are all "opposed" to it. Eastern Orthodox and Methodist/Weslyan are stated to view suicide as a sin. And, Reformed/Presbyterian and Anglican/Episcopalian aren't stated to have any opinion on suicide.
So, based on my research, which admittedly isn't much, most Christians are at least against suicide (if they don't outright view it as a sin) and a minority of them have no opinion on suicide.
It seems that the majority of Christians inherited this view on suicide from her Roman-Catholic origins (with the exception of the Eastern Orthodox church I guess), and the argument for sin being a person's death-sentence, if you will, to eternal life is that they can't repent in their lifetime because they're already dead.
But, my question is, how do we know this to be true? Where in the bible is suicide defined as "murder"? Or, should we try to analyze the meaning of the word "murder", maybe not only within the English language but perhaps the Hebrew language as well?
When I looked up the word "murder" on dictionary.com, I did find a biblical definition of the word murder, which stated
Wilful murder was distinguished from accidental homicide, and was invariably visited with capital punishment (Num. 35:16, 18, 21, 31; Lev. 24:17). This law in its principle is founded on the fact of man's having been made in the likeness of God (Gen. 9:5, 6; John 8:44; 1 John 3:12, 15). The Mosiac law prohibited any compensation for murder or the reprieve of the murderer (Ex. 21:12, 14; Deut. 19:11, 13; 2 Sam. 17:25; 20:10). Two witnesses were required in any capital case (Num. 35:19-30; Deut. 17:6-12). If the murderer could not be discovered, the city nearest the scene of the murder was required to make expiation for the crime committed (Deut. 21:1-9).
So, according to Easton's 1897 Bible Dictionary (where this information originated from), murder isn't simply the taking of another person's life but is done intentionally. If this is really how God views murder, then does this also include killing someone in self-defense? How about situations involving war or capital punishment, where an individual still has to take the life of another?
At least in Numbers, it appears that killing someone as the "avenger of blood" absolves one from any guilt of being a murderer. So, assuming that the "avenger of blood" would be the executioner of the murderer then the Bible does clearly leave capital punishment out of its definition of "murder". However, I didn't find any mention of killing someone in battle during war in Numbers. It's possible that someone who knows more about God's word better than me might be able to find a passage where war-time killing is excluded from the definition of murder, but that would be a distraction from the topic of my thread.
Based on what the book of Numbers says about murder, an act of murder has to satisfy three criteria:
- One person has to act in such a way that they end up taking another person's life,
- The act must be intentional, and
- It must have been committed out of hostility towards the deceased.
It seems that suicide falls short of the definition of murder, even if intentional, because it fails at least one criterion if not two criteria. However, that doesn't conclude that suicide isn't murder or that those who do commit suicide can still be saved, but so far it doesn't seem that there is a good argument for suicide being an act that prevents one from being saved.
citations:
- Comparison of Christian Denominations' Ethical Views. ReligionFacts.com. Retrieved November 6, 2010 from Comparison Chart of Ethical Views of Christian Denominations - ReligionFacts
- murder. (n.d.). Easton's 1897 Bible Dictionary. Retrieved November 06, 2010, from Dictionary.com website: Murder | Define Murder at Dictionary.com