Again, we only need to look at science objectively, without a bias... you aren't willing to do that. Neanderthals are the closest ancestors to humans that we are aware of, and archaeological studies of their remains show no signs they worshiped or had spiritual beliefs, they didn't seem to engage in rituals associated with spiritual belief. We know they existed on the planet at the same time as homo sapiens, but the species became extinct while homo sapiens thrived. Now of course, this doesn't prove that lack of spirituality was responsible for their extinction, but it has to be considered, since it's one of the only major distinctions between the species. We don't have evidence that something catastrophic happened, homo sapiens would have been effected as well, so something has to explain why Neanderthal became extinct and homo sapiens thrived.
We know from studies in Africa, as well as Australia, earliest civilizations of homo sapiens, practiced spiritual rituals and customs. They buried their dead with elaborate ceremonies using elements which can only be associated with spiritual belief. Throughout history of man, armies have been laid to waste in the name of stamping out religious spiritual ideology, and it still remains in mankind. Millions have laid down their lives in the name of their God, without hesitation, without regret... and millions more take their place as they become martyrs, the human spiritualism prevails and endures, as strong in man as it has ever been. Even Darwin would have to conclude, there is something to this, it's not 'fake' or 'phony' or unimportant. Human spirituality is indeed, a vital and fundamental part of humanity.