Most English translations of the Old Testament use two versions of the word “Lord.” “LORD,” in all capitals, translates the word YHWH, which is the name God revealed to Moses (Exodus 3:13-15). It means “I am,” referring to the God who truly exists and is ever-present. “Lord” usually translates Adonai, a more generic name for a lord/ruler/god. Sometimes, the translations use “Lord GOD” to translate the phrase Adonai YHWH. The translators did not want to translate this as “Lord LORD” so translated YHWH as “GOD.”

Since Hebrew does not use vowels, no one knows for sure how to pronounce YHWH. The best current guess is “Yahweh.” The ancient Israelites and Jews so revered this name that they would not pronounce it. Instead, they inserted the vowels for Adonai into the text, which produced the previous, mistaken English pronunciation of “Jehovah.” When they were reading the Scriptures out loud, the Jews would come to YHWH and say “Adonai.” 

Because of this, English-speaking Christians call God “Lord” since their Scriptures call Him LORD/Lord. This is a distortion of Scripture. As stated before, “Lord” (Adonai) was a generic name for God (similar to the English word “God”) used by many religions. So, when Israelites talked to other peoples, they might both use the word Adonai but have in mind two very different understandings of who God is. This led to much confusion. Therefore, there is much repetition in the Old Testament of the phrase “Name of God”—that is, YHWH—to distinguish the God revealed to the Israelites from the gods of all the other nations. This began with Abraham, who called on “the name of the LORD” (Genesis 12:8). In the law given to Moses, God said, “You shall not misuse the name of the LORD your God” (Exodus 20:7) and “Do not invoke the names of other gods” (Exodus 23:13). Sometimes the Old Testament just uses “the Name” (Leviticus 24:11, etc.).

In the third century BC, the Old Testament was translated into Greek for use by Greek-speaking Jews, Greek-speaking converts to Judaism, and Greek scholars who wanted to expand their libraries and were interested in what the Jews had to say. It was called the “Septuagint” translation because it was supposedly translated by seventy (or seventy-two) scholars. These Jewish scholars, following the Jewish hesitancy to pronounce the name YHWH, translated both YHWH and Adonai as kurios, which essentially means “Lord.” Therefore, when the writers of the New Testament (writing in Greek) quoted Old Testament passages, they quoted from the Septuagint, which did not distinguish between YHWH and Adonai. Following the Greek, English translations of the New Testament uniformly translate kurios as “Lord” even when kurios is a Greek translation of the Old Testament Hebrew YHWH, which English translations would normally translate as “LORD.”

Because of all this, Christians customarily call God “Lord” or “God,” which are not clearly distinguishable from other religions’ concepts of God—unless Christians are very clear in their own minds exactly who they are praying to.

Jesus also spoke of the name of God: “This, then, is how you should pray: ‘Our Father in heaven, hallowed be your name’” (Matthew 6:9) and “I have come in my Father’s name” (John 5:43). Jesus also spoke of His own name: “Whoever welcomes one such child in my name welcomes me” (Matthew 18:5) and “Where two or three gather in my name, there am I with them” (Matthew 18:20). If we remember that the name “Jesus” means “YHWH saves” (Matthew 1:21), then we realize that when Jesus used the term “name,” he was referring to Himself and to God the Father, that is, Yahweh. This identification is carried through by Jesus’ followers, who wrote, “Salvation is found in no one else, for there is no other name under heaven given to mankind by which we must be saved” (Acts 4:12) and “Everyone who calls on the name of the Lord will be saved” (Romans 10:13). This stress on Jesus as the only Name to offer salvation is very close to the Old Testament assertions that YHWH is the only God. Note also these verses: “[God seated Jesus] far above all rule and authority, power and dominion, and every name that is invoked, not only in the present age but also in the one to come” (Ephesians 1:21) and “God exalted him to the highest place and gave him the name that is above every name, that at the name of Jesus every knee should bow, in heaven and on earth and under the earth” (Philippians 2:9-10). Repeatedly, the New Testament writers refer to Jesus as “the Lord Jesus Christ” (Acts 21:13, 1 Corinthians 1:2,10, 5:3, 6:11, 2 Thessalonians 1:12, 3:6)—Lord here is kurios, the Greek word for Lord, which is also used to translate YHWH and Adonai, God.