Why I am not a Roman Catholic

The following is from James White, "On Really Believing the Gospel".

I am not a Roman Catholic because Roman Catholicism is a false religion. It is headed by an imposter, a man who claims to be something he is not. The Pope is not the Vicar of Christ, he is not the head of the Christian Church, he is not a "Holy Father," and I owe him no fealty, honor, nor respect in the religious sense. Roman Catholicism is a man-made perversion of the truth. While it retains elements of the truth (having moved away from the faith slowly and over a great deal of time), it falls under the condemnation of the Apostle Paul in Galatians 1. If the Judaizers were properly anathematized for their additions to the gospel, it is very clear to me that they never came close to dreaming up half the stuff Rome has added to the gospel over the centuries. Nor do we have any evidence that they attacked the sufficiency of Scripture, included grossly unbiblical offices (priests, Cardinals, Popes), or elevated anyone like Mary to the lofty heights of nigh unto divinity that Rome has over the past few centuries. The Papacy has embarrassed the Judaizers in the realm of innovation and gospel-corruption, to be sure.

So I am not a Roman Catholic by positive conviction that the gospel of grace found in Scripture is not the gospel of Rome. My positive conviction of the gospel that saves utterly precludes my consideration of Roman Catholicism, for to embrace that system would require me to abandon all I believe about Scripture (its inspiration, its preservation, its supremacy, its sufficiency), all I believe about the gospel (the sovereign decree of God, the perfection of the atonement, the power of the Spirit in bringing the elect to salvation), all I believe about the church (its form, function, and purpose). In other words, Roman Catholicism is a different religion than I profess. It is not just a variant, "another flavor."

One is either convicted that the gospel is something that matters or not. There really isn't any middle ground....

A true Protestant is a person who has made that act of will, that act of faith, in purposefully embracing the gospel of grace in opposition to a gospel of works and who recognizes that what he has embraced is fundamentally opposed to what he has rejected. The Apostle put it clearly and bluntly:

4 Now to the one who works, his wages are not counted as a gift but as his due.
5 And to the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness,
6 just as David also speaks of the blessing of the one to whom God counts righteousness apart from works:
7 "Blessed are those whose lawless deeds are forgiven, and whose sins are covered;
8 blessed is the man against whom the Lord will not count his sin."
(Rom 4:4-8 ESV)

Paul draws a 180 degree contrast between the faith of the one who does to receive and the one who believes. Clearly the Apostle did not think that the one "who works" was holding a "variant" of the same gospel....

So if you really believe the gospel, you really believe the negation of the gospel is evil. Just as the person who loves God and holiness will hate sin, so too the person who really believes the gospel will find its negation, its corruption, its perversion, an object of hatred.