God is commonly defined as omniscient and omnipotent. If he was created by something, he can't be either.
In the monotheistic sense, yes, but other cultures have exceptions to how much power a god can have. For most old pantheistic faiths, gods are higher beings with control over a certain aspect of nature. Some of them are without an origin of their own (the African god Bumba appearing out of space and literally vomiting the world), or can be spawned from a different being (Zeus and his siblings emerging from the titan Cronos). This day and age, God would be expected by most people to be perfect in all ways, but most civilizations had differing ideas as to what could truly be considered a "god".
Now that I think about it, there are also parts of the bible that suggest the Lord may not be omniscient. Among the earliest of examples is the book of Genesis after Adam and Eve eat the apple, they manage to hide from the Lord's sight in the garden. There are
plenty of contradictions on the matter of God's omniscience (among many, many other things.)
