This is a very strange thing to say, especially with such a broad brush, about people who aren’t Catholic and may be where I need to step out.
I, for one, believe that myself and my wife have a marriage that many should be able to confide in us for marital advice whether I’m Catholic or not.
It’s not about generalizing the idea of who knows how to explain love better. It is absolute truth that God is love, the embodiment of marriage. If there are people who seek the understand God’s love, they will be better equipped to explain how marriage should be like,
even if they aren’t married.
St. Thomas Aquinas taught that truths exist in every teaching, every experience, whether it’s the complete or partial truth. Your experiences have a lot of truths in it, but if it isn’t reflecting the perfect truth that is God, then it falls short from perfection, however, it can be very good advice, indeed. I say “can” because I don’t know what your advice will be, but I’m believe you do have good advice as you speak confidently about your marriage.
Let me just take an example that I hear being used to solve relationship problems in this day and age. A lot of people’s advice, Catholic or non-Catholic, for people who are fighting is for them to separate and take time apart from each other. I hear this portrayed like good advice when it’s not. It’s absolutely the opposite of what should be done. If anything, the couple should get even closer, forgive each other, love each other. That is what represents perfect love. Obviously, humans aren’t perfect beings with instantaneous though processes, so it’ll take time to figure out what to say, and sometimes we have to look to the Bible, God’s Word, for answers, but the longer the separation, the worse the relationship gets.
I’ve seen testimony from married Catholic couples who were on the brink of divorce that was given advice by a priest to look up what the Bible taught about marriage, and after, their marriage became stronger than ever.