Hate is blinding. When someone gets wrapped up in hatred of something, the hatred controls him and it prevents him from thinking clearly. Thus, people who are filled with hate will usually make bad choices and have a hard time discerning what is good and right. This is true for those who are Catholic and those who are not. Thus, when someone descends into the abyss of hating truth, it is even more difficult for that person to hear truth when it is spoken to him. Truth sounds like hate to those who hate truth.
This explains why there are so many today who refer to much of Catholic dogma as "hate speech". They hate the truth of God and so they can only see truth as being hateful. I have had people claim the most simple doctrines to be hateful--someone once said that it was hateful to say that God is triune. His rationale was that I was hating people who viewed God differently. Yes, I know that is utterly foolish, but I am only repeating the comment.
To those, on the other hand, who love the truth, the ability to discern truth is much more easily found. Yes, we still must listen carefully that we are not taken in by error, but when a person is genuinely seeking truth, his love of truth will help him to recognize it easily. Most of us are not perfect in this, so we must be cautious about our hearts and minds. We may love truth, and yet still be hanging on to a small piece of a lie that we cherish. Let us each subject our thoughts and ideas to the Lord on a regular basis, asking Him to grant us a deeper love for truth so that we can always recognize when we have fallen short of it.