Boyd’s Bible Dictionary:
(God). In Hebrew, Jehovah, “the self-existent and eternal,” and especially the covenant God. Generally rendered Lord. The ineffable name, not pronounced by the Jews, who substituted for it Adonai, “my Lord;” or Elohim—God, the creator and moral governor—when Adonai was written with Jehovah.

Concise Bible Dictionary:
The names by which God makes Himself known are various.

1. El, “the strong or mighty one.” It is often used of God, especially in Job and the Psalms (Job 5:8; Psa. 22:1, etc.); and of the Lord Jesus in Isaiah 9:6. It is also used for the false gods (Psa. 81:9; Dan. 11:36); and is translated “mighty” (Psa. 29:1; Psa. 82:1).

2. Eloah (Elah Chaldee), Elohim. The names most commonly used for God the Creator, the One with whom man has to do, the supreme Deity (Gen. 1:1-31). (Running all through the Old Testament to Malachi 3:18.) These words are also applied to God’s representatives, such as angels and judges (Ex. 22:28; Psa. 82:6); and also to false gods (Lev. 19:4). Elohim (which is plural, called the plural of majesty or excellency) is the word of most frequent occurrence. When it is distinctly used for the one true God the article is often added.

3. Jehovah. This is a name of relationship with men, especially with Israel, taken by God in time. It is derived from havah, “to exist,” and may be expanded into “who is, who was, and is to come.” God thus reveals Himself in time as the ever-existing One: that is, in Himself eternally, He is always the same (compare Heb. 1:12). The above “relationship” may be seen in the change from Elohim, the Creator, in Genesis 1, to Jehovah Elohim in Genesis 2, when man was brought into relationship with God. Again in Genesis 7:16 Elohim ordered Noah to make the ark but Jehovah shut him in. Unfortunately the name Jehovah is seldom employed in the AV. It is generally represented by LORD (sometimes GOD) printed in small capitals. In four places the AV has preserved the name Jehovah, namely, Ex. 6:3; Psa. 83:18; Isa. 12:2; Isa. 26:4.

There is a contraction of Jehovah into Jah, also translated in the AV by LORD, except in Psalm 68:4, where Israel is exhorted to sing unto God, and “extol Him by His name JAH.” Jah signifies the absolute supremacy of the self-existing One; whereas Jehovah was the name made known to Israel, and on which they could count. “God said unto Moses, I AM THAT I AM” (Ex. 3:14), where the word is Ehyeh, which is from the same root as Jehovah, the Eternal existing One; He that was, and is, and the coming One.

4. Shaddai, “the Almighty,” is another name of God, and is often so translated, especially in Job, without any other name attached (Job 6:4, 14; Psa. 68:14, etc). At times it is associated with one of the above words, and was the name by which He was especially known to the Patriarchs, as El Shaddai, God Almighty (Ex. 6:3): which passage does not mean that the Patriarchs had not heard of the name of Jehovah, but that it was not the especial name for them.

5. Elyon, “the Most High,” is another name of God, which stands alone, as in Deuteronomy 32:8 and 2 Samuel 24:14; and in Daniel 4:17-34 (from a kindred word); or it has one of the above words added and is then “the most high God” (Gen. 14:20); or “the LORD most high” (Psa. 7:17). It is not confined to Israel, for He is “the Most High over all the earth” (Psa. 83:18).

6-7. Adon and Adonai, and the plural Adonim, are all translated “Lord”; they occur frequently, and are found in some of the following compounds:

Adon Jehovah (Ex. 23:17), the Lord God.

Adon Jehovah Elohim (Isa. 51:22), thy Lord, the LORD, and thy God.

Adon Jehovah Sabaoth (Isa. 19:4), the Lord, the LORD of hosts.

Adonai Elohim (Psa. 86:12), O Lord my God (compare Dan. 9:3,9,15).

Adona Jehovah (Deut. 9:26), O Lord GOD (occurs frequently).

Adonai Jehovah Sabaoth (Jer. 2:19), the Lord GOD of hosts.

El Elohim (Gen. 33:20), El-elohe (Israel); (Gen. 46:3), God, the God (of thy father).

El Elohim Jehovah (Josh. 22:22), the LORD God of gods.

El Shaddai (Gen. 28:3, etc.), God Almighty.

Jah Jehovah (Isa. 26:4), the LORD JEHOVAH.

Jehovah Adon (Neh. 10:29), the LORD our Lord.

Jehovah Adonai (Psa. 68:20), GOD the Lord.

Jehovah El (Psa. 31:5), O LORD God.

Jehovah Elohim (Gen. 9:26, etc.), the LORD God.

Jehovah Elohim Sabaoth Adonai (Amos 5:16), the LORD, the God of hosts, the Lord.

Jehovah Jehovah El (Ex. 34:6), the LORD, the LORD God.

Jehovah Sabaoth (Jer. 46:18), the LORD of hosts.

Jehovah Sabaoth Elohim (Jer. 27:4, etc.), the LORD of hosts, the God (of Israel).

For titles in combination with Jehovah, see JEHOVAH.

The true pronunciation of Jehovah is declared to be lost: the Jews when reading the Old Testament never utter it (from a constrained interpretation of Leviticus 24:16), but say, “the name,” “the great and terrible name,” and the like.

In the New Testament the word Θεός is constantly translated God; and Κύριος is the word commonly rendered Lord. In the Old Testament the latter is used by the LXX as the translation of Jehovah, so in the New Testament it often represents Jehovah, and is then mostly, if not always, without the article, as in Matthew 1:20,22,24. The Lord is also called “the Almighty” (Rev. 1:8, etc.); and there are a few compound names as in the Old Testament:

God Almighty (Rev. 16:14; Rev. 19:15).

Lord Almighty (2 Cor. 6:18).

Lord God Almighty (Rev. 4:8; Rev. 11:17; Rev. 15:3; Rev. 16:7; Rev. 21:22).

Lord of Sabaoth (Rom. 9:29; James 5:4).

The characteristic name of God in the New Testament in relationship with His saints is that of FATHER: it was used anticipatively in the Lord’s intercourse with His disciples, but made a reality after His resurrection, when He sent the message: “I ascend unto My Father and your Father, and to My God and your God” (John 20:17).

THE TRINITY. In reference to this term the Father is God (Phil. 2:11; 1 Thess. 1:1, etc.). The Lord Jesus is God (Isa. 9:6; Matt. 1:23; John 1:1; Rom. 9:5; Phil. 2:6; Col. 2:9; 1 Tim. 3:16; Heb. 1:8). The Holy Spirit is God: “the Spirit of God moved upon the face of the waters” (Gen. 1:2). Ananias lied to “the Holy Ghost,” “unto God”; and Sapphira unto the “Spirit of the Lord” (Acts 5:3-4, 9); “Spirit of God” (1 Cor. 2:11; 1 Cor. 3:16, etc). That there are three divine Persons (if we may so express it) is plain from scripture. The Father sent the Son, and He came to earth. The Father sent the Holy Spirit, and the Lord Jesus sent the Holy Spirit, and He came from heaven. He is a divine Person, of which there are many proofs (see HOLY SPIRIT). There is but one God.

Scripture reveals what God is in Himself, “God is love” used absolutely (1 John 4:8); and “God is light” used relatively, in opposition to darkness (1 John 1:5); and Christ is the expression of both in a Man. The principal of God’s attributes and characteristics as revealed in scripture are—

1. His Eternity (Hab. 1:12; Rom. 1:20).

2. Invisibility (Col. 1:15).

3. Immortality (Psa. 90:2; 1 Tim. 1:17).

4. Omnipotence (Job 24:1; Matt. 19:26; only Potentate. 1 Tim. 6:15).

5. Omnipresence (Psa. 139:7-10; Jer. 23:23-24).

6. Omniscience (1 Chron. 28:9; Isa. 42:8-9; Rom. 8:29-30; Heb. 4:13).

7. Incorruptibility (Rom. 1:23; James 1:13).

8. Immutability (Mal. 3:6; James 1:17).

9. Wisdom (Psa. 104:24; Rom. 11:33-36).

10. Holiness (Psa. 47:8; Psa. 99:3, 5; Rev. 4:8).

11. Justice (Psa. 89:14; 2 Tim. 4:8).

12. Grace and mercy (Psa. 136; 2 Cor. 1:3; Eph. 2:4).

13. Longsuffering (Ex. 34:6; Rom. 9:22).

14. Faithfulness (Psa. 36:5; Heb. 10:23).

God’s eternal power and divinity may be known in creation (Rom. 1:20); but He has revealed Himself in the person of Christ, the Son, the eternal Word. God has been pleased also to reveal Himself in His written word. His purposes, His ways, and what He has done for sinful man, all demand universal reverence, adoration, and worship.