Theology: the study of religious faith, practice, and experience : the study of God and God’s relation to the world : a system of religious beliefs or ideas
Polytheism: the belief that there is more than one god.
Atheism: the belief that there is no god.
Agnostic: one who cares not to argue the existence of God one way or the other.
These are your choices. Differences exist within the realm of theology as to His identity and how to worship that God. Judaism, Islam and Christianity are all based on the God of Abraham. They worship the idea of the same God in different ways. Some other religions exist that are not Abramic in origin, yet see the clarity of requirements for a monotheistic belief system.
I somewhat understand Judaism from an outsiders point of few since Christ was from the tribe of Judah. Being a follower of Christ my theology is Christian based. I have studied for decades and still there are many mysteries to uncover, if ever that may happen. I have not studied the others.
Recently I offered my opinion on this blog. I called it just that, my opinion. I even offered it up in bold text to make that point clear. Opinion is not doctrine, but since theology is theoretical in nature, being a study, because I have an opinion, it is part of theology, but it is not doctrine.
Job 6:24-26 Teach me, and I will hold my tongue: and cause me to understand wherein I have erred. How forcible are right words! but what doth your arguing reprove? Do ye imagine to reprove words, and the speeches of one that is desperate, which are as wind?
I will allow these words to speak for themselves.