The Old Testament was originally written in Hebrew and Aramaic. The Hebrew word translated "Lord" comes from a word in Hebrew whose consonants are represented by the English letters YHWH. Because of the lack of vowels in ancient written Hebrew, scholars have long debated how this word was pronounced. The two most common pronunciations are Jehovah (a Latinized pronunciation used since the 16th Century) and Yahweh (an attempt to pronounce the word according to a more literal Hebrew rendering).
What is the tetragrammaton? What does YHWH mean?
The word tetragrammaton, meaning "four letters", is often used as the technical term to refer to this Hebrew word. In early Judaism, the word was used as the Lord's name. However, by the time of the Temple's destruction in 70 A.D., the word was considered too holy to pronounce. The Jewish Mishnah (a book of early Jewish traditions) even states, "He who pronounces the Name with its own letters has no part in the world to come!"
Another tradition that developed regarding the use of God's name is to not write out the full name of God due to its holiness. Instead, sometimes different letters or hyphens are used. In English, it is common to see Jewish writings that refer to God in written form in English as G-d.
Early Jewish Christians likely continued the tradition of saying the word "Adonai" (another word for Lord) in place of the tetragrammaton, but had no particular rules against verbally saying or writing the holy name. As Christianity expanded beyond Jews to include non-Jewish believers, the practice of not saying or writing the holy name for God from the Old Testament became less common.
However, still today adherent Jews will say Adonai in place of Yahweh when reading Scripture as well as refer to God as G-d in writing. These practices are not commanded of Christians but are certainly not wrong, as their intent is to give honor to God and pay respect to His name. The practice of not saying or writing God's holy name is a matter of personal choice.
Of greater importance is one's belief in the one, true God (Deuteronomy 6:4-5) and faith in His one and only Son Jesus Christ (John 3:16). Salvation is based on God's grace through faith alone in Jesus Christ alone (Ephesians 2:8-9). No work, despite its sincerity, brings salvation. Yet respect and reverence for God and His holiness is also a biblical command that is represented in many ways. For some, this includes the tradition of how one refers to God's holy name.
The name of God Yahweh or YHWH is often connected with His revelation to Moses in Exodus 3:14 where "God said to Moses, 'I AM WHO I AM.'" God is the self-existent One, the I AM, who is worthy of all worship and honor.
What are the names of God? What do the names of God mean?
What is the difference between LORD, GOD, Lord, God, etc. in the Bible? What does each mean?
What does holy, holy, holy mean in reference to God?
What is the fear of God?
The attributes of God, what are they?
Truth about God