I don't believe in heaven and hell or the concept of an afterlife where you retain the entirety of who you were when you were bound to your body.
The essence that is "you", your thoughts, feelings, memories etc., can be boiled down to the concept of energy. That's how I think of it. We are just one frequency among a symphony of them so to speak.
When you die, the shell that contains that essence is left vacant. The flesh memories left behind in that shell are their own type of energy and what animated you is simply a different kind. It's all energy.
But everything here, the entirety of the universe as we know it, is energy. Just a massive flow of energy, bonding and forming and creating and evolving. I agree with the concept that energy can neither be created nor destroyed, merely redistributed.
By that logic, we are a never-ending flow of energy and those energies coalesce into me or you or that tree or that rock or that star or that planet or what ever.
Reincarnation is simply "like recognizing like" and being drawn to each other. You get enough in one place and then you get past lives.
Or soul mates, of which I believe you have many. Those people that you are drawn to without explanation as if your pieces fit their pieces and you've always been part of a whole....it's simply energy being drawn to energy that has flowed together since before time was even a concept.
Something like that anyways. It's the only thing I've been able to come up with that makes any kind of sense to me.