There is no concrete proof that anything happens after death. There's no evidence that the spirit lives on in anyway. It's all superstition stemming from a fear of death -- or rather, non-existence.
Think about it: animals are born, they live, then they die. Do we believe in an animal afterlife? No. The concept is only used to console young children who have lost a cherished animal. So if animals "just die," and if we humans too are animals, what should make us think that we're any better?
The problem is our intelligence. We're smart enough to fear death, unlike animals. When animals fight to survive, they're merely following instinct -- their inborn reflexes. When humans fight to survive, though there is instinct involved, we mainly struggle because we WANT to survive. We don't WANT to die.
As previously mentioned, the idea of nonexistence can be a bit uncomfortable -- even overwhelming. To just poof! not exist anymore IS scary. At least at first, it is. But once you live in the real world and look only at FACTS, you'll plainly see that any other ideas are just that: ideas. There's no disembodied spirit in us. We ARE our biological minds.
To look for an afterlife is to avoid accepting reality.