The parable does not really begin in verse 24. It flows out of what Jesus said three verses earlier. Before the two builders, there are people who call him Lord, Lord. These are not atheists. They are not cursing Jesus. They are calling him Lord, and not once but twice, which is fervent and emphatic. Their confession is orthodox, because every believer confesses Jesus as Lord. It is public, because it comes with prophecy and mighty works. On paper, that confession checks every box.
And yet Jesus says the most terrifying words in all of Scripture: I never knew you; depart from me. How can someone say all the right words and do all the right religious things and still hear that? Here is the answer. There is a difference between agreeing with Jesus and submitting to Jesus, and most people never figure out that difference. They gladly follow the parts of the Bible that already line up with their common sense. They underline the verses they like. But agreement does not test us very much. Anybody can agree.
The real test comes when God’s will crosses ours. When his Word tells us to do something painful, something strange, something that runs against every natural desire we have, that is where we find out whether we are agreeing or actually submitting. Morris points out that the doubled Lord, Lord expresses apparent devotion, yet Jesus makes obedience, not profession, the mark of the real thing. You can agree with a King you have never once obeyed.