Jesus wants to see our lips and our lives align. Hence he ends His Sermon on the Plain with this most searching of rhetorical questions: “Why do you call me, ‘Lord, Lord,’ and not do what I tell you?” He saw a contrast between what people were saying and how they were behaving, and He wanted to call them to perform a serious spiritual self-examination. He wanted them, just as He wants us, to see that a verbal profession of faith in Him must be accompanied by moral obedience to Him.

Jesus did not teach that entry into the kingdom of heaven is through the good works of obedience. Salvation is by grace alone, through faith alone, plus nothing (see Ephesians 2:8). All that we bring to Christ is the sin from which we need to be forgiven. What, then, is He teaching? Simply this: that only those who obey Him—those who express their faith by their works—have truly heard and have been transformed by the gospel. As the Reformers observed, it is faith alone that saves, but the faith that saves is not alone. The apostle John, picking up on Jesus’ words, says in his first letter, “If we say we have fellowship with him while we walk in darkness, we lie and do not practice the truth” (1 John 1:6). Scripture makes it clear that the manner in which we hear and obey Jesus’ words has significance for all of eternity because it reveals the true state and reality of our faith.

No accumulation of visible religious works and no number of religious words will be able to disguise our private behavior from God. The real test of those who name the name of the Lord, says Paul—and let’s not evade for one instant the chilling demand of this—is that they “depart from iniquity” (2 Timothy 2:19). Therein lies the evidence of genuine faith.

While none of us will live a perfect life, we are all called to live changed lives. We live under the lordship of Christ; His Spirit is now within us. Will we have complete success? No. But we will be different, and our lives will increasingly demonstrate that we have “turned to God from idols to serve the living and true God” (1 Thessalonians 1:9). So consider your own life. Do you call Jesus Lord? Good! But, crucially, can you point to evidence in your life—in what you do not do and in what you do, in the temptations you fight and the virtues you strive for and the forgiveness you repentantly ask for—that He is truly your Lord?