“I’m really questioning if Roman Catholicism is a subset of Christianity.”
It’s certainly not the gospel of grace apart from works that Paul learned from Jesus (he didn’t learn it from men). They refuse his appointed authority from the risen Lord, forever running back to Israel’s things and times, BEFORE God revealed His awesome redemption via the Cross, and the sublime HEAVENLY salvation fully realized in Ephesians.
If Martin Luther did anything, it was to promote the liberating gospel he learned FROM PAUL (and that is anathema to Rome’s Labyrinth of works religion).
Agree. We see a fairly simple structure in the NT Church.
If that is compared to the current structure of Roman Catholicism we can how its veered off the straight and narrow.
In the NT we see the clear teaching that all have sinned and fall short of the glory of God, yet in Roman Catholicism an exception has been carved out.
In the NT we see that all sin separates us from God yet in Roman Catholicism we see two different types of sin in the "venial" and "mortal".
We can go on and on with the contradictions Roman Catholicism and the New Testament.