Humans are emotional critters hence our weird un-animal-like behaviour. Even without intervention some humans would likely invent a spiritual 'excuse' in their lives, because that is the nature of the beast.
Daft things like love, hate, anger, frustration, happiness, sadness etc are all difficult to explain but present all the same. Some people are just more spiritual than others and there are things like religion to fill the void. I'm not religious but I accept that we are all different and some people are.
And there will always be nutters.