Afterlife is a very rational, natural consequence of the order of things.
After all, nothing is ever lost—even the body only transforms into earth. But nothing is lost.
So too, the person you are is never lost. That person—that soul—only returns to its origin.
If your soul became acutely attached to the material world during its stay here, then it must painfully rip itself away to make the journey back.
But if it was only a traveler, connected to its source all along, then its ride home is heavenly.