1) What more or less justifies Christianity is Jesus' New Covenant, which is supposed to incorporate the Ten Commandments and Beatitudes, while freeing us from the problematic aspects of the Old Testament.
2) Despite theories of Roman contamination (and there are some), the Council of Nicaea was a well-intended carrying forward of Jesus' ideas.
3) The Protestant Reformation was a well-intended "cleansing" of some corrupt Catholic practices, including indulgence selling, simony, too-powerful & naughty priests, icon worship, etc.
4) Unfortunately, Martin Luther (not the first to oppose the Catholics), took liberties with new Bible translations, and made the Protestant church into an Old Testament, faith-based cult (in an apparent effort to further discredit Catholics and Jews).
5) The original Bible actually talks about the merits of BOTH faith and good works (“You see that a man is justified by works and not by faith alone” James 2:24). In Luther's time, the Catholics were skewed towards good works (as were the Puritans, an Anglican offshoot). The problem with faith alone is it allows phonies like Trump to claim the cachet of a believer, wo any commitment to action.
6) Additionally, the "Holy Spirit" concept may have been hijacked by charismatic offshoots, when it may have been intended as a practical trinitarian exponent of God and Jesus.
7) I'm not sure, but "Faith only" and "Are you full of the Holy Spirit?" have become somewhat vague concepts which cause divisions within the church and are hard to govern around. Was this done to wield power over people, in a big-tent snake oil kind of way?
8) Why not just go back to the New Covenant, Ten Commandments, and Beatitudes? Much simpler, but then many don't have the courage or discipline to simply "love thy neighbor".
