Paul Earnhart on Matthew 7:21-23:
With language that has become even more piercingly plain, Jesus turns from the false prophets to the false professors and their false standards. It is dangerous enough for a man to take the broad road to destruction on purpose, but it is infinitely more dangerous for him to take it, believing it is the way to life. Enthusiastic shouts of “Lord, Lord” can be nothing more than a convenient bit of fleece to cover an unyielding heart. There may not be a wolf beneath the sheepskin, but there certainly is a goat! Empty professions are as dangerous to the narrow road as false prophets.
There is nothing untoward about an earnest confession of faith in the Son of God and the open acknowledgment that He is Lord. Indeed, there can be no true discipleship without it (Matthew 10:32-33; Romans 10:9-10). But the tragedy sets in when that is all there is—a mouthy declaration of Jesus’ sovereignty without any evidence of submission (Luke 6:46).
Invitation to a Spiritual Revolution: Studies in the Sermon on the Mount