Feuerbach wasn’t entirely wrong. Projection is a real thing. Anthropomorphism is well known: that we can project human characteristics onto animals. When it comes to Feuerbach and God, I think he just throws out the baby (that humans can know anything of God) with the bathwater (humans are prone to projection). For him, projection is a reason to doubt any/all knowledge of, and hence the existence of (for who can be bothered believing in something you can’t know!?) God. For me, projection is the temptation to make God into a mere idol.
But the salient insight here is the importance of knowing self (and your tendency to project – or indeed your tendency to dismiss the possibility for any knowledge simply because full/perfect knowledge seems impossible) in the quest to know any ‘other’. Both the knowing subject and the known object must be a part of any thoroughgoing epistemology.