TrickyFish
SNA
The Future of an Illusion is a good Freud text to read which directly discusses the philosophy of religion. However, it does rely on some aspects of psychology when discussing things like our need for a god as a father-figure. Freud is a great critic of religion, along with works like Nietzsche's On the Genealogy of Morality, Feuerbach's Essence of Christianity, and David Hume's Dialogues Concerning Natural Religion.