I don’t think that people can get truth about God unless God first gives it to us in some way: through revelation.
Put another way, I don’t think it is possible to be “orthodox by accident.” When we seem good themes in popular, secular culture, for example, we shouldn’t automatically think, “Oh, that’s good, this movie/book/song/speaker/etc. is compatible with Christianity; I can accept and embrace the message of this movie/book/song/speaker/etc.”
No, it is better to say that while all humans are capable of recognizing some truth – and are even capable of doing very good, admirable deeds – there is no one who truly seeks God without God drawing him or her in the first place (John 6:44; Rom. 3:10-18).
You can stumble onto some truth, of course (it’s pretty tough to be wrong about everything!), but you cannot stumble, by accident, into a relationship with God – and that is what Christianity entails: proper relationship with God. Therefore, everything that looks like it is on the side of Christ – and yet explicitly denies Christian doctrines about Christ – is not, in fact, on the side of Christ. To think that simply being “good” in a few ways should set us right with God is like thinking that being a model citizen or “good person” alone could make one a good son or daughter; however, whether one is a good son/daughter depends on one’s relationship with one’s parents.
Think about it: if you had a son and he grew up to be a model citizen, perfect in every way – best job, best income, best education, best manners, best physique, best social standing, etc. – and yet he never called you, never acknowledged you, never responded to your calls, and even taught his children that they had no grandparents … would you call him a good son? What if he volunteered a lot and saved many lives during some crisis after a natural disaster? Would he be a good son then? What if he was a decent guy who never wanted to hurt anyone and yet never acknowledged you at all? Would he be a good son? What if he was always very friendly to his neighbours and even gave away all his possessions to those in need? This might be pleasing to you at a distance, but would he be a good son?
Clearly, the answer is “No.” And I would argue that, in the same way, you cannot be a good creature in a vacuum; you cannot be a good creature without acknowledging your Creator: being a good creature, by definition, means relating properly to your Creator.
So if some movie/book/song/speaker/etc. has good values, great – but does it do anything to move people toward right relationship with God by addressing the problem of sin, advocating for repentance and belief in the gospel so that they might be made alive spiritually? Because if you get that part wrong, it doesn’t matter what else you get right.