The difference between Christianity and secularism is not the difference between two competing
worldviews, faiths, or philosophies, but a difference between a meaningful universe and and objective silliness. The project of secularism has not been to assert anything non-religious (for indeed, how could one assert a ‘non’?) but to rename the religious. The cathedral becomes the museum, Christmas becomes Wintertide, Charity becomes philanthropy, the ethics of Christ become the ethics of ‘rational and advanced human beings’ (with modifications), the sacrament of marriage becomes a ceremony, the City of St. Francis becomes San Francisco, baptism becomes a useful literary symbol, we forget the ‘holy’ in ‘holiday,’ the ‘God be by you’ in ‘goodbye,’ as the French forget the ‘a dieu’ (to God) in adieu — this ‘renaming’ is really no more than a separation of things from their origins and of words from their meanings. The universe that results is obscure, awkward, ill-fit, absurd — everything without explanation. But this is the perverse blessing of secularism, that the degree to which everything is without explanation is the degree to which Christianity asserts herself as the explanation.
There's much more and it's truly rich.
Consider passing it on to that friend of yours who's constantly haranguing religion in general and Christianity specifically.
Watch the veins in his neck bulge.
You know that's fun.