If I may. Everyone needs to be satisfied in their own minds that they're doing the right thing-and we're all called to to do the best we can with what we know. In fact the Catholic church, for its part, teaches that a person must never go against their own conscience, especailly in religious matters, even though she also recogonizes that our consciences may well be mis- or under-informed. For myself, raised Catholic and leaving at a young age, I later came to believe as Luther did-until later yet I was to come to understand the error in his beliefs.
The main treasure, so to speak, of a church or denomination is their doctrine, their body of teachings regarding the will of God for man: what it means to be right in His eyes, for the purpose of our salvation. And the Reformers left much of that teaching behind, teachings that the Eastern churches also held and hold to this day. Luther taught that the crux of the difference between his and the Catholic position centered around justifaction: the doctrine of Sola Fide-and he was absolutely right. What I would come to understand, and to appreciate more and more, is that the ancient teachings, consistent with Scripture and the ECFs, is much more balanced and sound, and consistent with experience as well, compared with the Reformed teaching where Sola Fide has caused confusion regarding the role of faith and what, exactly, is required of us in general to be right in God's eyes.
None of this means that Protestantism is bad, or doesn't serve God and lead people to Him and can't produce good fruit in general. But it does mean that confusion has been introduced into Christianity, resulting in extreme differences in teachings in many cases, more so every day now, resulting primarily from another doctrine, that of Sola Scriptura, a doctrine which claims to be able to authoritatively ensure us of knowing God's will while ironically been the primary source of this confusion and disagreement. And Luther, himself, was concerned about this potentiality. Once authority to know the truth is removed from the church which received the teachings at the beginning, then the faith becomes a sort of free-for-all, because each reader of Scripture actually becomes their own authority.