Everybody positions themselves in relation to God one way or another. Everyone chooses whether or not to affirm God as real and then as relevant. There are theists, agnostics, atheists and antitheists.
True theists affirm God and treat Him as relevant. Agnostics and atheists are functionally the same – both believe that God is irrelevant, even if real (this category includes deists). Antitheists consider the idea of a relevant God to be dangerous, especially when real.
True atheists and agnostics are relatively benign. They have no stake in God one way or the other. They must live and let live. No offense can be taken.
True theists must determine how best to express their convictions. They must give God His due as they understand it. They can choose whether or not to tolerate those who do not.
True antitheists have no such choice. They are defined by their animosity toward God and must oppose all expressions that affirm God and His relevance. Many who call themselves atheists and are aggressive in their disdain are actually, by definition, antitheists.
When did God become the enemy? What fuels such antipathy toward God?