How do you study and teach a subject that you believe has no basis?
You drink a lot.
Philosophers traditionally study many branches of philosophy which they feel are wrong or disagree with basic tenants of. Among other methods one might use to study religion as a secularist are: historical analysis, (ie: The Catholic Church had it's first scism in 459 A.D. over the issue of the Pope, comparative doctrine; (ie: Christian scientists believe Mary Eddy was the prophet while Seven Day Adventists believe Edith White was teh prophet), textual analysis (ie: the first copy of Jonah is found in the scrolls found in Al'Baka valley in 1933), etc.
I'm no rocket scientist - but I've shot my share of bottle rockets....
Actually, if the person approaches the subject from a purely academic perspective, it may actually be a benefit to teaching the subject, because biases may be set aside to truly understand the foundations of what is to be taught. This thought is better expressed by Pierre Abelard:
"The beginning of wisdom is found in doubting; by doubting we come to the question, and by seeking we may come upon the truth."
Two of the individuals quoted in the CSM article, Dawkins and Harris, fail the above. In fact, I find them an embarrassment, similar to others the article mentions. Then again, when one is 'enamored with their own press', vision can be fairly blinded.
Maybe it does have a basis. Evolution is religion.
I have encouraged people to read the afterword of Anne Rice's novel about Jesus as a child, "Christ the Lord"--even if you don't care for the book (and the book was OK), the afterword was amazing. A personal spiritual testimony, and also a narrative of her research in the US's religion
departments at several universities. She expresses a perplexity about "so many professors hating their subjects" and points out that usually a scholar has some emotional attachment to their chosen subject, but that religion PhDs despise both the faith and the faithful.