In Leviticus 22:32, G-d commanded: "You shall not profane [treat as common] My holy name, but I will be sanctified among the sons of Israel." When they heard this command, the Israelites wondered how they were supposed to obey it. They decided to use circumlocutions and evasive synonyms to avoid directly using G-d's Names or titles. If G-d's Name were written on something that was thrown in the trash, burned, or otherwise defiled, then His Name would be mistreated and profaned!
G-d also commands Israel to talk about Him and His ways frequently: "You shall speak of them when you sit in your house and when you walk by the way and when you lie down and when you rise up." (Deuteronomy 6:6-7) But using G-d's Name that often would make it part of their ordinary, every-day speech. How were they do obey this commandment and the one from Leviticus not to profane His Name? Even in their daily discussions, Jews sanctify G-d's Name. For millennia, they have avoided speaking the sacred Name of G-d and instead say HaShem" (Hebrew for "The Name").
After Israel's return from the Babylonian Exile in the sixth century BCE, Ezra, Nehemiah, and the men of the Great Assembly firmly established circumlocutions as the rule. As a consequence, the Septuagint (the Jewish translation of the Hebrew Scriptures into Greek during the third century BCE) frequently replaces the sacred four-letter Name of G-d with Kurios ("Lord"). This replacement is the reason why we often see Yeshua (Jesus) and the disciples referring to G-d as "the Lord." Although the Hebrew Scriptures contain a few circumlocutions (most notably in the Psalms), the New Testament records the Master and the disciples using them regularly.
The most notable circumlocution in the New Testament is "Father." Although the Old Testament never uses "Father" to refer to G-d, Yeshua frequently refers to Him as "your Father who is in heaven" (Matthew 5:16) or "your heavenly Father" (Luke 11:13) and uses other similar paternal evasions. He is the first to use this label and does so to distinguish between Himself and the One Who sent Him. Yeshua came from the Father (John 16:28) and during His time on Earth was subordinate to the Father (John 6:38, Hebrews 10:7, John 14:28, etc.). His first-century audience would have clearly understood the picture of a "Father" and "Son" origin/subordination but "Father" is only used metaphorically. There was no disembodied spirit-father-and-spirit-mother-give-birth-to-a-son scenario since no other deity/"goddess" has ever existed (see Isaiah 45:5 and others). Unbelievers have frequently mistaken this metaphor as the New Testament writers importing pagan or Greco-Roman religion in which gods and goddesses often mate and produce offspring. That's not the case. Messiah simply uses "Father" to describe a relationship metaphorically.
The New Testament also records "Heaven" as a circumlocution for G-d's Name. In Luke's Gospel—written to a Gentile audience—Messiah says: "he who is least in the kingdom of G-d is greater than he." (Luke 7:28) However, Matthew's Gospel—written to a Jewish audience—records the same event but the Master's words are "the one who is least in the kingdom of heaven is greater than he." (Matthew 11:11) The prodigal son, upon his return to his father's house in disgrace, declares: "I have sinned against heaven and against you." (Luke 15:21) Did the prodigal son sin against the sky or the stars? No, "Heaven" was a typical first-century circumlocution referring to G-d.
Believers today often pray to our "Heavenly Father" and encourage one another to seek the "Kingdom of Heaven". If we speak in these ways, we sanctify G-d's Name, follow the example of Scripture, and echo the words of our Lord and Savior. Blessed be His Name.