Hardcore materialists reduce mankind's spirituality into solid matter. Reality is only preceived through the senses and the brain.

From what I've seen, they use logic to make their points that seem to go in circles and end up with more confusion, uncertainty and darkness than what they started with. There is no light at the end of the tunnel on this path.

Any spirituality in the term "I am" is lost" when the "I am" is dropped from the term "I am a brain." The person becomes trapped in a brain (a creation) as opposed to being a free spirit creator. 

There are some materialists, however, who see consciousness as more than just the product of a brain.  

An atheist had his materialistic point a view changed it when he had a near death experience.   His consciousness was expanded into spiritual realms.

Near-death-experiences can open realities and possibilities that most of us can only dream about. NDEs can be consciousness expanding events.

Dr. Stephen Greer had a near death experience in 1973 that opened up his mind to the possibility of communication with extraterrestrials. He called this CE5 (Close encounters with aliens initiated by a human being.) He's been practising these CE5 techniques for 40 years with some success.

If a person is going to learn by his mistakes, he has to have a better storage place for memories than his brain where they can be easily destroyed. The akaskic records is one such place. This is the advanced backup memory system plugged into the minds of earthly souls. 

On Star Trek, memories can be recreated through the use of a holodeck and holograms. Some of these holograms end up as sentient beings.  

Personally, I've tried to use advanced memory systems as a way to understand Jesus Christ and The Kingdom of Heaven better. "Ask and it will be given. Knock and the door will be opened to you."

Is there a spiritual side to mankind? Check out the movies "Field of Dreams", "Ghost" " What Dreams May Come" and ask yourself what are they really about? 

P.S. Further evidence on Near Death Experiences.