Protestants believe in sola scriptura, which means the Bible is the ultimate authority for the Christian life. Catholics believe that Scripture and Sacred Tradition are both authorities, and the authoritative magisterium provides binding interpretations of them.
Here’s why Catholics can’t embrace sola scriptura.
The Bible itself rejects the idea.
Nowhere in Scripture does it claim to be the sole authority for the Christian life. Jesus doesn’t tell His apostles to write Gospels; rather, He commissions them to preach the Gospel.
If you claim that sola scriptura is true but can’t find it in the Bible, you’re appealing to another authority outside of Scripture.
The Bible offers Sacred Tradition as an authoritative guide.
In 2 Thessalonians 2:15, St. Paul says, “So then, brethren, stand firm and hold to the traditions which you were taught by us, either by word of mouth or by letter.”
“By mouth or letter” sounds a lot like Scripture and Sacred Tradition!