Only months into my mission we stopped to meet a man that had grown up Mormon but had left the Church and was now attending a Method Church with his wife and family. He was very interested in his forgotten Mormon heritage and enjoyed having us stop by to talk religion.
On one of our visits he showed us a book called Who Needs God by Harold Kushner, a Jewish Rabbi. He lent me the book to peruse. Mission life does not leave a lot of time for reading books, but for the sake of having discussions with him I read through parts of the book, picking out topics that sounded interesting. To this day I still haven’t read the whole book, but enjoyed the parts I did read very much. Kushner is a very insightful man.
One passage that I read blew me away because it gave such a comprehensive definition of monotheism:
The affirmation of monotheism – that there is only one God – is a moral statement, not a mathematical deduction. If there is only one God and He demands moral behavior, then there can be such a thing as good and evil. (Technically speaking, right and wrong are matters of fact: Who stole the money? Good and bad are matters of morality: Should I take the money?) When there are many gods, as in pagan legends, the issue is not: What is good? The issue is: Which God shall I serve? Which one has the power to protect and reward me? Think, for example, of the conflicts of Homer’s Illiad, where the gods take sides. What pleases one displease another. A person offends one of the gods but is under the protection of another, stronger one. The issue is not what is right but who has the might.
The assertion that there is only one God is the assertion that issues of moral behavior are not matters of personal taste. We cannot decide by majority vote that it is all right to steal and lie, any more than we can decide that winters should be mild or cookies more nourishing than vegetables.
I paused in my reading. With a sudden flood of understanding, I comprehended that I and all Mormons are monotheists and always have been. Our doctrines of the plurality of gods and of the exaltation and deification of humankind do not change our monotheistic status, as defined by Rabbi Kushner, any more than the Trinity doctrine changes other Christian’s monotheistic status.
Based on this moral definition of monotheism, we Mormons do indeed believe there is exactly one God and that there was no God formed before God and there shall be no God formed after God. (Isaiah 43:10)