Had a reader ask if I should have read Dan Brown's Da Vinci Code.
Here was my response.
Philippians 4:8 kept me from reading Da Vinci for quite a while.
What got me reading it was:
1. Hearing whiffs of the questioning of the New Testament witness. I wanted to know how this was questioned.
2. I'm giving the early church history classis exam next Tuesday, so wanted to be familiar, as several heresies from then are represented in the book.
3. I came across it at the library, so it was convenient.
4. People say (I'm not sure) it's the best seller of all time, besides the Bible.
I almost never read novels like this b/c of Phil 4:8. Only when several factors converge like these do I consider it.
Be assured there wasn't gratuitous and detailed sexual stuff in it beyond one scene. (Sidenote: gratuitous means not necessary to the plot - added for sensationalism; it doesn't mean excessive). What was more wicked than the description of the sex rite was that the main character "grew" from being initially horrified by it, to understanding it was a natural, worshipful thing to do. THAT is the concern, far more than the exposure to the sexual.
I believe there are things mature Christian adults can read/watch that immature Christians shouldn't. This seems to be the point of Romans 14-15. Part of maturity involves discerning and filtering stuff well, so you are edified by the good and not corrupted by the bad. But this shouldn't be used as an excuse to take in immorality either. Nor should we read something, just because we can.
Sin (swearing, sex, whatever) depicted in a work of art isn't always gratuitous (without purpose). It becomes so when it strays from the author's literary purpose. (As a side conclusion, it isn't always a sin to depict sin in art.)
A better question than "what is okay to read?" is "What is the best to read?" Think Andrew Stanley's question: what's the wise thing to do/read? instead of "what can I get away with reading?"
We don't want to fill our minds with evil and untruth, but you must know the lie in order to refute it. Just dismissing Dan Brown without answering him is the church's temptation today, but his basic assertion questioning the NT texts must be answered b/c people are obviously believing it.
Balance of quantity in what you read is part of the equation here. Keep your reading 4 parts Bible, 3 parts great Christian thinkers (Augustine, Athanasius, Aquinas, Calvin, Luther, Edwards, Puritans), 2 parts great classical literature (Plato, Melville, Shakespeare, Dumas) and 1 part contemporary stuff. See CS Lewis' "On the Reading of Old Books" for more there.