What is the difference between LORD, God, Lord, God, etc. in the Bible? What does each mean?

from the old testament

• In most English Bibles, sometimes a passage says “LORD,” with all caps, while at other times, just “Lord.” Likewise, sometimes a passage will read, “GOD,” yet, at other times, simply “God." The reason for the differences is because the English Bibles are translating three Hebrew words into two English ones. Using all capital letters helps distinguish the third word from the other two.
• To understand why that is, and to start with the easy part of the explanation, the two words with regular capital letters (“Lord” and “God”) are direct translations of two Hebrew words. The word “Lord” is a translation of adonai. Adonai is a generic word that refers to a lord or master. For example, when Jeremiah was speaking to King Zedekiah, he said, “Now hear, please, O my lord (adonai) the king” (Jeremiah 37:20a).
• Though adonai is a generic word, it is more commonly seen with the first letter capitalized because it refers to God. For example, “Tremble, O earth, at the presence of the Lord (Adonai), at the presence of the God of Jacob” (Psalm 114:7).
• Similarly, the word “God” is a translation of the generic word elohim. It is a word that can be used for pagan gods, such as when God told Israel to stop committing idolatry so that He would again be near them. “…if you do not go after other gods (elohim) to your own harm, then I will let you dwell in this place” (Jeremiah 7:6–7).
• However, though it is used generically, it is often used for the true God. When used for Him, the first letter is capitalized. For example, God said, “I declared and saved and proclaimed, when there was no strange god among you; and you are my witnesses…and I am God (Elohim)” (Isaiah 43:12). Notice that both adonai and elohim are generic words. To distinguish between when they are used generically and when they are used to refer to the true God, the first letter is capitalized. In contrast to those two words, “LORD” and “GOD” are used to translate one Hebrew word, namely God’s personal name, YHWH (generally pronounced “Yahweh”).
• Though God gave His name to be remembered by His people (Exodus 3:14–15), over time, it was avoided out of fear of violating God’s command to not use His name in vain (Exodus 20:7).
• Hebrew does not have vowels like English, so YHWH is just the consonants. Because saying God’s name was prohibited, when Jewish scholars began adding vowel markers to help people pronounce the words correctly, they intentionally used the wrong ones for YHWH. When a Jewish reader reads the Old Testament and sees YHWH, they verbally replace YHWH with the word to which the vowels belong.
• In most cases, that word is adonai, as it’s usually the word whose vowels are added to YHWH. English translations translate YHWH with adonai vowels as “LORD” with all caps. This is done to let the reader know that the actual word is YHWH, in contrast to adonai, which is translated simply as “Lord.” For example, Exodus 19:8 reads, “All the people answered together and said, ‘All that the LORD (YHWH) has spoken we will do.’ And Moses reported the words of the people to the LORD (YHWH).”
• However, sometimes the Hebrew says “Adonai YHWH.” In those cases, YHWH is given the vowels from elohim to avoid confusion with the word adonai right before it. Otherwise, Jewish readers would say “Adonai Adonai,” which would sound weird. English translations translate those instances of YHWH with “GOD.” Like with “LORD,” “GOD” in all caps indicates to the reader that YHWH is the actual word, distinguishing it from times when the translated word is elohim. For example, talking about feasts, Exodus 23:17 reads, “Three times in the year shall all your males appear before the Lord (Adonai) GOD (YHWH).”
• God never prohibited using His name. Most English Bibles translate the way they do to follow the tradition of replacing YHWH with another word. However, some translations, such as the new Legacy Standard Bible, translate YHWH as “Yahweh.” In either case, we have freedom to say LORD, GOD, or Yahweh.

from the new testament

• The all-capitalized words LORD and GOD do not exist in the New Testament. Only two generic words are used. “Lord” is a translation of kurios, which has a similar meaning as adonai. Likewise, “God” is a translation of theos, also a generic word like elohim.
• Interestingly, when the New Testament authors quoted verses from the Old Testament that referred to YHWH, they used the generic word kurios. This confirms that there is nothing wrong with the English translations that use “LORD” or “GOD” instead of “Yahweh.” For example, Paul quotes Joel 2:32 in Romans 10:13, saying “Everyone who calls on the name of the Lord (kurios) will be saved;” whereas Joel said, “It shall come to pass that everyone who calls on the name of the LORD (YHWH) shall be saved.”
• Because of the New Testament’s use of kurios for YHWH, when they called Jesus “Lord,” they were not merely saying that He was their master. They were saying He was Yahweh. Notice that in the previous Joel passage that Paul quoted, it is the name of Jesus, the “Lord” (kurios in Greek and YHWH in Hebrew), who saves.

implications for today

The name YHWH is special because it is God’s personal name. This is why, even when translating it as LORD or GOD, English translations of the Old Testament are careful to distinguish it from the generic words for “lord” and “god.”

YHWH gave His name so that He could form a personal relationship with us. He did this to show how great His love, mercy, and grace are. In other words, He gave us His name so that we might know Him and worship Him.

However, God is holy and cannot dwell with sin. Therefore, He had to deal with our sin before He could form an eternal relationship with us. This is why He sent His Son, Jesus. Jesus came and never sinned. Because He is perfect, He did not have to die, but He did so willingly. When He did, the Father punished Jesus for all the sins of those who believe in Jesus’s name.

The foundation for a relationship with YHWH is through…YHWH! As Paul said, we must call upon the name of the Lord, Jesus. This means repenting of our sin and confessing that He is YHWH. This is not a formula prayer where we say the name of Jesus and then get saved. Rather, it is understanding that, because of His sacrificial death, He is the only way of escape from God’s wrath against sin. In other words, evidence of true salvation is the ongoing, genuine expression of our trust and faith in His life, death, and resurrection.