Ghost and God

I was watching Discovery channel series 'A Haunting'. It's a TV series comprised of narrations and dramatic reenactments of paranormal encounters and experiences based on real experiences. This is the first time I saw the series. I usually don't watch anything related to paranormal but today I did. Anyway the series got me thinking.

Do I need to believe in God in order to believe in Ghost?

Let me explain. Ghost is supposed to be spirit of deceased who either have some unfinished business or some attachment on Earth that keeps them from moving on. But moving on to where? In order to explain that, don't I have to believe in God?

The only explanation that I can think is based on Bhagwad Gita that talks about recycling of souls without mentioning God. According to the Gita:

The body is temporary but the soul is eternal. When this body is finished the soul must continue to exist as it's eternal. And just as the soul is currently residing in this body, when this body is finished the soul will continue to exist by residing in another body. (From: Gitamtra.org)

So in this case I don't have to believe in God and still can believe in ghost, do I? Or is there something I am missing?