God of the gaps means whenever you cannot explain some thing then "god did it." I know of no other thinking process, except superstition, to define it.
Science is all we have. All of life, indeed, all of the universe is so complex we can’t possibly know all the answers. We can observe and describe and think and still we don't have all the answers; we may never know them. It is to rationalize to say “god did it”! How do you know that? By what authority do you make that claim? Is your authority trustworthy? Is god the only answer, or is it Allah, or Yahweh, or one of the gods of Asia or Africa or Australia or Scientology?
Monotheism is about dictatorship. In Christianity, god made man. Judaism was stricter. Islamic God is about submission. The one God of all three monotheistic religions expects obedience. Each claim theirs is the One True God.
Religions is a construct, an idea, a thought, told verbally at first, then in writings that are labelled “holy scripture”. These, too, are constructs. These constructs, created at first by Stone Age peoples, then goat and sheep herders, in an attempt to explain things they did not understand. This is what has come to us through the ages.
Religion eschews doubt, they claim it is the voice of evil. How can that idea be justified? Doubt is what awakens observation and exploration and experimentation! How do we know that two means two? We have evidence that defines the word. What evidence do you have that religion holds the answers to the processes of existence? Doubt is the engine that moves reason, thinking, and wondering. I doubt seriously that it can be any other way.
Some people replace god with ghosts, spirits, and other constructs. There is no evidence for the supernatural. If there were then there would be something to reveal it. God, as the other supernatural things, are imaginary.
There is a 99.99% probability that there is no god. I state it this way because of the burden of proof. If I tell you that absolutely no god exists then I have to prove this as fact. Nobody can prove it either way.