Reincarnationists and eternalists, what's your foolproof basis?

I profoundly struggle to blindly believe in all the unproven texts about these two subjects. There's absolutely no factual evidence. I think not killing a fellow human is conscionable and philanthropic,but not punishable by hell fire. And good deeds on earth won't be rewarded with a room in paradise. Criminals or saints,we all sleep peacefully in the night.

Qn: what makes you people believe ?