It was good to read about the journey of someone who came out of Rome and about the reasons why many are becoming disenchanted with the RCC. Castaldo gave some good insights into what it like to live under the authority of the Magisterium and how we Evangelicals can help others come out from under its shadow in a redemptive manner. I agree that one of the key issues is Rome's claim to be the only infallible authority to interpret the Scriptures, a claim which is contrary to the biblical truth of sola Scriptura. However, I think the more critical issue is the heart of the gospel, justification. The imputation of our sin to Christ and the imputation of Christ's righteousness to us (2 Cor. 5:21), the "blessed exchange," is denied by the RCC and,consequently, Roman Catholic teaching negates the Word of God.