observing the lingo of atheists reveals the same kind of "absolute" commitment to Materialism - this is, unfortunately for religious people, totally in line with all available evidence. There is no evidence - repeat NO EVIDENCE - for a spirit realm or for "ghosts in the machine".
Atheists and scientists accept the existence of lions because of the evidence. They don't currently accept the existence of Bigfoot or God or the Flying Spaghetti Monster because there is no evidence for them.
Atheists simply share a lack of belief in spirits, spirit realms, God, gods, etc. That says nothing about materialism, evaluating evidence, bigfoot, lions or the FSM.