And it came to pass, that, as they went in the way, a certain man said unto him, Lord, I will follow thee whithersoever thou goest.
Luke 9:57
Lord is one of the most popular names of God the Son in the New Testament, appearing hundreds of times.  These two verses show that this name, from the Greek word kurios, is used in two distinct ways in the New Testament.
In the first verse, from Luke’s Gospel, the “Lord” used of Jesus is a term of respect, similar to our use of mister or sir in modern society.  This “certain man” respected Jesus, but he apparently had no intention of committing his life to Him as his spiritual Lord and Master.  He did not reply when Jesus told him about the sacrifice He required of His followers (see Luke 9:58).
Even Jesus’ disciples sometimes called Him Lord in this polite, respectful sense. For example, Jesus once told a parable about the need for people to wait and watch expectantly for His return. Peter approached Him and asked, “Lord, speakest thou this parable unto us, or even to all?” (Luke 12:41).
As Jesus’ earthly ministry unfolded, the polite title of Lord that people used of Him was transformed into a declaration of faith in Him as the divine Son of God the Father. This is the sense in which the apostle Paul calls Jesus “Lord” in 1 Corinthians 15:58.
After His resurrection and ascension, Jesus became the Lord of history, the Lord of the church, and the Lord of individual Christians. When we declare that “Jesus is Lord,” we submit to His lordship and crown Him as the supreme ruler over our lives.