The phrase "all men are created equal" comes from the
United States Declaration of Independence. It doesn't specifically mention God. The full phrase is:
"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."
Therefore, it was Thomas Jefferson, as the primary author of the Declaration of Independence, who wrote this phrase. The declaration alludes to a "Creator," but does not explicitly state that this creator is God.