And with regards to the 2nd people might reason that if the last thing you do is kill yourself then you have no chance of being forgiven cause you will not have asked for it after the "sin".
Not Biblical, and nonsensical too. Logically, that would mean anyone who died having sinned after their last prayer would be hellbound as well, which is probably everyone. Think about it for a second. Does that mean someone who dies of a heart attack while having sex with someone other than his/her spouse is also going to hell? What about someone who tells a white lie or spreads gossip about someone else and then drops dead? Or someone who dies a violent death and whose last words are along the lines of "God damnit!" (using the Lord's name in vain)?
The ancient Jews death with that by performing "yearly" (probably actually monthly, based on lunar cycles - they were nomadic and don't have access to solar calendars) rituals including animal sacrifices and putting the sins of the community onto a goat, which they then banished into the desert (this is the origin of the term "scapegoat", incidentally). The Catholics have last rites and prayers for the deceased, and I think Eastern Orthodox Christians do something similar. Christian denominations that come from Protestantism, which is basically all the rest, note that being completely free of sin is not a Biblical requirement for salvation, and in fact, the Bible seems to indicate otherwise - "all have sinned and fallen short of the glory of God", the only thing required for salvation is an acceptance of Jesus (think that comes from the story of Jesus' crucification along side two other criminals). In fact, this was one of the top reasons for the Protestant Reformation - the Catholic Church fleecing folks by selling "indulgences" and last rites and post-death prayers to fast-track folks into heaven, despite none of that being remotely Biblical. In fact, 8 suicides are mentioned in the Bible, 3 of which are viewed at least somewhat positively, and 5 of which are related factually with no apparent value judgement whatsoever. None of the suicides in the Bible are condemned. If anything, that suggests the Bible says suicide can be a moral decision.
Of course, it's hard to ignore the usefulness of "suicide sends you to hell" as a money-making tool in the old days, and a social control method or a suicide prevention method among the religious these days, so that seems like the only reasonable explanation for the perpetuation of that particular point of view among Judeo-Christianity.
