Hell is nonsense, but pretty much every religious teaching I studied/read about condemns suicide in a way or another. Exceptions are (correct me if I am wrong), Shinto (which isn't a religion, technically) and also some really underground religion I forgot the name (there is a page about it on wikipedia, but there is no way I am looking for it now).
Whether that means people really try hard to control what others do with their live through religion or it means killing yourself is definitely a bad thing, well... That is up to the person's interpretation. But it is not something exclusive to Christianity and similar religious teachings.
I don't have an opinion on it. All I can do is hope nothing bad awaits me.
For starters the entire concept of hell is very immoral. Eternal torture for a finite crime? How could you be happy in heaven knowing people are being tortured forever on the basis of belief? Something that isn't even a choice.(For instance I can not choose to believe Florida is in the arctic circle, I would have to be convinced by new information etc Religious beliefs work the same way.)
It also makes no sense. We are supposedly condemned because Adam and Eve ate from the tree when they did not know the difference between right and wrong.
1) How it is wrong if they did not know the difference between right and wrong?
2) This story goes against evolution.
3)Free will clear does not exist. So it makes absolutely no sense to blame the watch instead of watch maker.
4) Later Jesus sends his son to die to on the cross (human sacrifice)
5) Stays dead for 3 days(How is that equivalent to eternal torture? or even much of a sacrifice)
?6) How does belief(or guil ability based on where you were born(religious beliefs are largely culture ie if you are born in India you will be a Hindu instead of christian etc,) which is not even a choice determine heaven or hell for all of eternity?
7) What is the point in hell? Eternal torment? After a billion years the person still needs to be tortured? What is that going to do?
8) Praise God eternally in heaven? How much of an ego does God have that he created creatures to praise him forever?
Judaism and Christianity do not condemn suicide. Islam has a verse condemning suicide. Pagan religions do not condemn suicide. Commandment 6 is usually used against suicide. Commandments 6-10 refer to other people, not self. So Thou shalt murder refers to others not self. God backs and enables Samson suicide. It's pretty easy to argue Jesus committed suicide by cop. There is nothing is the Torah or bible that says suicide is wrong. It just weird interpretations the church ran with in response to suicide pacts. The church was concerned largely for economic reasons.
"Life is a gift" does not makes sense a gift by definition. A gift by defintion means you were giving something without expecting in return. If you expect something in return it's not a gift.
"God's will that we stay alive, so its going against God will to kill ourselves."
Absent a guide or instruction manual, If we all have to go on is a creator that has given us life we can't infer that suicide is against God's will. If we accept that it is against God's will to kill yourself, why would is also not be against God's will to save someone life ? A person is walking along a street about to get hit by a bus so you push them out of the way, should the person respond with how dare you do that !? It's against God's will! It was God's will I be hit by that bus! If we are a doctor should we say I must not save the patient, it's God will that they die ? No one says that. Why is the argument any better in the case of suicide ? You might say it's was God's will that I save your life, so why not say the same thing about suicide ? It's was God's will that I be in this situation and God's will that I kill myself. Absent any special instruction manual from God, God's will argument cuts both ways. We do not know if it's God will that we act or God's will that we do not act. Absent an instruction manual from God. So this argument is dismissed as can't conclude it's for or against God's will.
"Instruction manual from God says it's against God's will."
For instance someone may say the bible says suicide is wrong. Since the bible is God's word we must do what it says. There are a lot of assumptions behind this argument we would need to really analyze. Is there a God ? Has God expressed his morality in a book ? If so what book ? Do we have moral reason to obey God ? If we do have an obligation to obey instruction manual are we prepared to actually obey it ? Even if there is a sentence that says not to commit suicide, (as in Koran) there are a lot of other things in the instruction manual that we are not inclined to do. The instruction manual tells you that if a teenager is rude to their parents they should be stoned to death. How many of you think that is a moral requirement ? If you are going to pick and choose what parts of the instruction manual you think are morally relevant, than you can't come to me and say suicide is wrong because the instruction manual says so. As you are not really using the instruction manual to give you moral guidance. You are starting with your moral beliefs and picking and choosing which bits and pieces of the instruction manual you want to accept.
Etc