I didn't see the quotation as being anti-religion. I saw it more as a caution against defining oneself primarily in terms of extrinsic
categorisations. We are not born Christian, Muslim, English, African, etc., etc. We only acquire these labels through learning from others that we are part of the group that defines itself in that way.
I think he's suggesting that as soon as we define ourselves in terms of one particular group, rather than just as a human being, those who are defined differently, immediately become "the other" and that is where conflict arises.
Easier said than done though.