“What separates me from most so-called atheists is a feeling of utter humility toward the unattainable secrets of the harmony of the cosmos. The fanatical atheists are like slaves who are still feeling the weight of their chains which they have thrown off after hard struggle. They are creatures who – in their grudge against traditional religion as the ‘opium of the masses’ – cannot hear the music of the spheres.” - Einstein
Before I became a Christian, there were certain people who came into the room and it was like a "light on them", later on a found out they were Christian. So, this could be how a Christian is seen by an atheist. Atheism is essentially life as a "wild animal" with no spiritual pursuit or interest, so it must come as a shock when they see someone outside their limited realm of materialism.
If you're taught you're a soul less animal and then feed hateful music into your head constantly. Atheism creates are moral void, this void filled with hateful music, creates "atheistic terrorism" ( First seen in Columbine Shooter "Natural Selection Shirt" constant exposure to "Hateful Death Metal" same as this case.