The Catechism of the Catholic Church teaches that “justification includes the remission of sins, sanctification, and the renewal of the inner man” (CCC 2019). Protestants deny that the last two of these are part of justification. How can I show that they are?
Look up Romans 6:7. All standard English translations render this verse as some variation on the statement, “He who has died has been freed from sin.” The topic here is one of sanctification, the making the believer holy, or freeing him from sin.
What is significant about Romans 6:7 is that when it says the one who has died has been freed from sin, the word for freed is actually the Greek word for justified. What it literally says is, “He who has died has been justified from sin,” yet the context is so obviously sanctificational that all standard English translations of the Bible rendered “justified from sin” as “freed from sin.” This shows that for Paul there was not a rigid wall between justification and sanctification. The meanings of the two terms overlap in his mind.