Gods/ deities are immortal, spiritual beings. They vary in cultures in the way of style, character and ability. Most are percieved as all powerful, and benevolent. Captain Hatch claimed that He was going to make the Humans "fear the Gods". Perhaps some are good and others are bad.
It is confirmed that the supreme being, God, exists and created most things in the universe and is the only true omnipotent being. The identities and powers of other "gods" are yet to be confirmed.