There’s SOOOOOOO much that keeps me Catholic, but to limit my response I’ll just talk about simple logic. If you look at the Protestant claims to legitimacy–and I mean really look at and analyze them–they fall apart quite easily. First and foremost is the fact that sola scriptura absolutely disproves sola scriptura. There’s lots of ways this is true, but one of them is just by virtue of the fact that the scriptura they’re so sola about is an abridged, edited version of the Bible. If sola scriptura was valid, it would encompass the entire Bible and not just the cherry-picked, edited version handed down by Luther.
Another way sola scriptura disproves itself and all Protestantism is that, if sola scriptura were true, there would be one, single, unified Protestant church, not 42,000 varied denominations.
One easy one–so easy I tend to not bring it up except to friends who’ve never given apologetics any thought–is that sola scriptura is not only un-biblical, it’s anti-biblical. Not only is it not mentioned anywhere in the Bible, but the Bible specifically states that you should rely on tradition as well.
Another bit of logic that utterly disproves all Protestantism is the fact that their basic narrative is that Jesus founded the One True Church, the Catholics (or Constantine) corrupted it at some point in the first 100-500 years of its existence and it became the invisible church for 1000-1400 years (or longer), only to be revived by Luther, Calvin, Jimmy Swaggart, etc. For that narrative to be true, Jesus (who said, “upon this rock I will build my church; and the gates of hell shall not prevail against it”) has to be a liar and, therefore, all of Christianity is false. Either Jesus is a liar or Protestantism is false.
There’s more, but I believe those are plenty. Like someone else mentioned, check out Trent Horn’s “Hard Sayings.” Devin Rose’s “The Protesttant’s Dilemma” is a great one, too.
