There could be a god and no afterlife. There could be an afterlife and no god. I personally find the former more likely than the latter.
Why? They both seem equally likely (even assuming non-zero probability).
How could there be an afterlife?
Does your afterlife theory include the idea of a soul?
How can a soul exist? What organ is responsible for it? And how does it use energy after the body is dead?
Or does your afterlife theory include defying the laws of nature? (i mean, in order for the soul idea to be possible, it would have to have some mechanism for using energy, or the afterlife theory would have to defy the laws of nature.)
If this contradiction is not resolved in your afterlife theory, then why do you think it has a likelihood of being true?