For Darwinists religion is a kind of illusion?

The predisposition to religious belief is the most complex and powerful force in the human mind and in all probability an ineradicable part of human nature

Since the time of the Greeks, science and religion have been two of the chief contenders for the role of human-produced systems or activities that yet in some sense and for some reason transcend the human experience. Religion gives ethical commandments, which are important for group living; also it gives a cohesion to human kind which is a social lubricant or super glue.

 For much of the Christian era, it was religion particularly that was taken as the enterprise above all that tells of something over and above the lives of us mere mortals. But since the Enlightenment in the eighteenth century, increasingly, it has been science that has taken the front role and made the strongest claims as something that goes beyond the daily existence of humankind and tells of the deeper truths about reality. So long as religion was firmly in the driver’s seat, it was happy to take science along as a passenger— less metaphorically, science was seen to fill out certain areas of knowledge and understanding within the overall picture provided by religion;  

Darwinism explains Religion (including Christianity) as a kind of illusion: an illusion that is necessary for efficient survival and reproduction. Once this explanation has been put in place and exposed, one might take the view (and many do) that Christianity has no reflection in reality. In other words, epistemologically  (how we know what we know) one ought to be an atheist.