Roman Catholics vs. Evangelical Protestants
Justin Taylor, quoting Biola's Robert Saucy on the difference between Roman Catholics and Evangelical Protestants:
They’re the same as they were at the Reformation. There are three significant ones.
First is the question of final authority. Protestants hold to sola scriptura [Scripture as their final authority]. For Catholics, the final authority is Scripture as interpreted by the church, that is, the magisterium (the pope and bishops). That’s where Catholicism gets its teachings that can’t be found in Scripture, like veneration of Mary, indulgences and purgatory.
Second, Catholics view the church as an extension of Christ’s incarnation. For them, the church is divine as Christ was divine. One result of this is the Catholic proclamation: “Come to the church for salvation, for faith in the church and faith in Christ are one act of faith.”
That leads to the third difference: salvation. The Catholic catechism makes it very clear that you are born again and justified through baptism. That means faith plus a certain rite — which is administered by the church — is necessary for salvation. So, the church essentially grants salvation. Although this salvation is “by faith,” additional grace enables us “to work” to attain eternal life.
And that’s the problem with saying we speak the same gospel. One of them is clear: Christ did it; we can’t add anything to that. The other one is: Christ did it, but to actually avail yourself of what Christ did you have to do this and this.