I guess by your statement then that Catholics are not Christians? Really?
Only Christians heed the WORD of God appointed by God and Christ that Paul is the minister to the Gentiles and that Paul was given the gospel of grace and that when God shall judge the secrets of men by Jesus Christ according to my gospel.
Anyone call call themselves a Christian, but if they “profess” that Jesus Christ is their “savior”; but - if they are laboring under the delusion that they must DO “something” (some sort of “WORKS”) in order to KEEP their salvation they are TAKING AWAY from the “FINISHED WORK” of the Lord Jesus Christ on Calvary and ADDING to the Gospel of the Grace of God!
When the Lord Jesus Christ spoke the words “It Is FINISHED” [John 19:30] - you can bet your soul that there is NOTHING that we can DO to ADD to that “FINISHED WORK”! The Lord Jesus Christ did NOT die and shed His blood just for the sins that I committed BEFORE I believed on Him and received Him as my Savior!
1 John 4:10 Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins. {ALL OF THEM!}
These qualities mark a Christian believer.