Why Do Christians Call Jesus Lord?

Before Jesus was born, Jewish people had a practice: they avoided saying the name YHWH — the covenant name of God given to Moses in Exodus 3:14. When they read the Scriptures aloud, they substituted the Hebrew word Adonai, “Lord.” When the Old Testament was translated into Greek (the Septuagint, which Paul and the apostles knew well), they used the Greek word Kyrios — “Lord” — wherever YHWH appeared. For every Jewish reader, Kyrios in the Old Testament meant God Himself.

This is the word the New Testament keeps using for Jesus.

Paul writes, “if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved” (Romans 10:9). A few verses later he quotes Joel 2:32 — “whoever calls on the name of the Lord shall be saved” — and applies it directly to Jesus (Romans 10:13). In the Old Testament, that verse is about calling on YHWH. In the New Testament, Paul says that promise is fulfilled in Jesus.

Philippians 2 is even sharper. Paul takes Isaiah 45:23, where God says, “To Me every knee shall bow, every tongue shall take an oath,” and applies it to Jesus: “at the name of Jesus every knee should bow... and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father” (Philippians 2:10–11). The worship Isaiah said belonged to God alone, Paul says belongs to Jesus. That is not a slip — it is the point of the passage.

Thomas, after the resurrection, says, “My Lord and my God!” (John 20:28). He puts Kyrios and Theos side by side, and Jesus accepts it. Peter tells the crowd at Pentecost, “God has made this Jesus, whom you crucified, both Lord and Christ” (Acts 2:36). The earliest Christian creed, according to scholars across the board, is just three words: Kyrios Iēsous — Jesus is Lord.

So why do Christians call Jesus Lord? Not because it sounds respectful. Because the New Testament pushes the Old Testament’s word for God onto Jesus deliberately, repeatedly, and without apology. The apostles were Jewish monotheists. They did not use this word lightly. They used it because they believed Jesus is the Lord, YHWH in the flesh.

This is also where it becomes personal. In the Roman world, “Caesar is Lord” was the required confession of political loyalty. To say instead, “Jesus is Lord,” was dangerous. It meant: Caesar is not ultimate; the risen Jesus is. That confession cost many of the earliest Christians their lives. They kept saying it because they knew who He really was.

Calling Jesus Lord is not only about theology. It is about allegiance. If Jesus is Lord, then He is Lord over your money, your relationships, your fears, and your future. You cannot confess Him as Lord on Sunday and live as your own king on Monday. Lordship is the point where faith stops being a theory and starts reshaping a life.

That is why Christians call Him Lord. Because the Bible does. Because the apostles did, to the point of dying for it. Because the risen Jesus is ruling right now. And because if He is not Lord of all, He is not Lord at all.