I believed in god 100% when I was a kid, when I grew older I started to have my doubts so I asked him, honestly, for a little proof of his existence, guess what, he didn't send me anything. God is fictional. As an example of the absurdity of heaven:
I'm walking with my girlfriend and a robber tries to rob us and shoots her. I was a believer but she wasn't.
50 years later, the robber and I both die, the robber a few years before dying accepts jesus christ and repents his sins.
We are now both in heaven and I'm supposed to be happy knowing that not only my girlfriend is going to be eternally tortured but also that I'm going to spend all eternity living with the man who actually killed her.
Furthermore if she lived maybe she would have accepted jesus christ just like the robber did yet she didn't have the chance to do so.
Humans in our current state are utterly unfit for eternal life.
If you have Netflix I recommend the dark and disturbing series Altered Carbon. It explores what humanity would do if we discovered a technology that allowed us to upload ourselves into new bodies and use this technology to live forever. The series set some 300 years in the future.
What would we do with eternal life? Simple we would turn the earth into a living hell. The series is so dark because it so accurately describes human nature.
Both the Catholics and the Jews believe in purgatory. This is a place where the evil in us that makes us unfit to enter heaven is purified aka burned away. If there is a heaven the need for such a place follows logically from the utter darkness in human nature.
What does it mean to "purify" an evil that is inherent to our very nature. Well it means that a big part of what we are the darkness has to be burned away and die. If that is 95% because you like to shoot and murder people then I imagine such a purification would be rather unpleasant. I certainly would not want to be the guy who has to have 95% of who he is consumed by a burning purification of truth so that a deeply remorseful 5% suitable for eternal life and can continue.
Can someone who died in their youth or did not have a chance to fully explore the devine be saved? To the degree they lived their life in alignment with truth and that anyone can be saved they certainly could be. Nowhere in the Bible does it explicitly say that unbelievers cannot be saved after death. Clark Pinnock a prominent Christian theologian is a compelling author and defended this line of reasoning.
https://www.amazon.com/Wideness-Gods-Mercy-Finality-Religions/dp/0310535913The take away message is that we should align ourselves with truth and the transcendent to the core of our being. To the degree we succeed we transform ourself into something suitable for an afterlife and prevent the manifestation of hell on earth.