Which would you rather watch: a movie that promotes pagan ideology, or a movie about Jesus that gets a few things incorrect theologically? Most Catholics would choose the latter. Now, the harder question is, which would damage your soul more? It might seem like the former, because we all know how bad paganism is. Yet, there is another question to ask: do obvious errors hurt us more than hidden errors?
Someone pointed out to me a book that many Catholics have read (and liked) and I noted that it was written by a protestant and that he was encouraging a non-catholic attitude. The person said, "yeah, but it's such a good book otherwise; is it really a big deal?" You think about it: is it a big deal to be deceived and led down a path of behavior that contradicts the teachings of the Church? Yup, I would say that is a big deal.
Now, chances are, few Catholics (who are not in a state of grave sin) would enjoy reading a book promoting paganism. Yet, it should be clear that when we know something to be an error, it is easier to resist it and avoid being deceived by it. When something is "kinda close" that can be more destructive to our souls. We (as the person I mentioned above) can let our guard down and end up accepting, little by little, errors that creep into our soul and lead us away from the Church.
In the end, then, which is worse? An obvious lie, or a subtle lie? If we are truly on guard for the lies of the devil, neither will harm us, but that is rarely the case. We slip at times, we get casual about things, and because we want to find the truth, we can get confused as to the difference between something "mostly true" and something "completely true".
Let us all be "on guard" against the errors; not just the big ones that are obvious and easy to spot, but also (and even more so) the little ones that we might not notice. Remember, just one degree off the mark will take us miles away from our destination over time. Jesus said He is "the Truth" not "most of the truth". Stay in the truth and do not give in to anything that is "mostly true".