On a certain Orthodox podcast, the host was positively gushing over the writing of a certain kofer, apikorus, מחטיא את הרבים [he should live a long life - but first do teshuva].
WOW!
OK - You want to read his blasphemy, that is your בחירה חופשית prerogative. Bad idea but free country. But don't tell your audience that you do without the caveat that it is absolutely assur. Much worse than not waiting between eating meat and milk [which I am sure he does] or talking during שמונה עשרה [which I am sure he is careful not to do]. This aveirah erodes the basic foundations of our faith, of EVERYTHING.
An entire volume has been authored on this topic with sources and details - "הרחק מעליך דרכך" by Rabbi Yisrael Kalman Krohn ztz"l.
Which brings me back to 9th grade. I literally remember NOTHING that my 9th grade biology teacher taught me. Not a word. Except for the day he introduced the unit on the theory of evolution. He told us that we don't have to believe it but we have to learn it for the Regents.
I must say that I look back and wonder about the wisdom of teaching young impressionable boys a theory which on the face of it contradicts everything they are taught to believe. Ahhh - but what about the Regents??? Well, would they teach a course that requires the students to view pornographic magazines in order to pass the Regents?? I think not. It is the same pasuk - לא תתורו אחרי לבבכם refers to kfira and אחרי עיניכם refers to pornography. They are equally bad but I would venture that the RESULT of the former aveira, the collateral damage, is worse than the latter.
Instead - we have a different option!!! We can learn sfarim which STRENGTHEN our faith. I often wonder about those OTD'ers who go off the derech before familiarizing themselves with the entire gamut of literature that bolsters and enhances faith in our Tradition. Like, she learned through Tanach, Medrashim, Shas, Kuzari, Moreh Nevuchim, Derech Hashem, Kisvei HaMaharal [especially באר הגולה], Kisvei Maran HaRav Kook, Kisvei HaRav Amiel, Kisvei HaRav Soloveitchik, Kisvei HaRav Lichtenstein etc. etc. and decided - "naaaaah, don't buy it". Not only unlikely but never happened. In the meantime, exactly ZERO proofs have been marshaled to disprove the existence of G-d.
But belief isn't [to use a popular word today] "binary". It isn't whether you believe or you don't. There are infinite LEVELS of belief and disbelief. Our DAILY AVODA is to strengthen and enhance our faith in every which way. R' Chatzkel Levenstein said he worked on his Emunah for 40 years and ONE DAY that he doesn't work on his Emunah, he feels it weakening. He DIDN'T mean that he started doubting the existence of Hashem. He meant that on his level - it wasn't the same.