If we define God as the giver of life, then technically Lister is God to everyone, not just the Cat. He created the Cat race, he taught Kryten to break his programming therefore gain free will therefore life, and his existence is the reason Rimmer was revived and continues to be revived. Dave Lister created and sustains the life around him merely by existing and, personally, I think there couldn’t be a better man for the job.