I beleive it is written that those whom beleive in Jesus and accept him into their lives will have their sins forgiven and be given passage into heaven. It is also written with Jesus saying (and I am paraphrasing) "If you call out my name only in your last hours, I will say I do not know you" Thats pretty straight forward in my book, if you do not beleive in Jesus, you will not be allowed eternal life in heaven. And dont try only when you realize you are about to die and burn in hell. :)
(but I'm not the formost autority on religion, far from it in fact)