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Vine's Expository Dictionary of NT Words [1]

1: Βελίαλ (Strong'S #955 — Noun Masculine — belial — bel-ee'-al )

is a word frequently used in the Old Testament, with various meanings, especially in the books of Samuel, where it is found nine times. See also  Deuteronomy 13:13;  Judges 19:22;  20:13;  1—Kings 21:10,13;  2—Chronicles 13:7 . Its original meaning was either "worthlessness" or "hopeless ruin" (see the Rv , margin). It also had the meanings of "extreme wickedness and destruction," the latter indicating the destiny of the former. In the period between the OT and the NT it came to be a proper name for Satan. There may be an indication of this in  Nahum 1:15 , where the word translated "the wicked one" is Belial.

 2—Corinthians 6:15

Fausset's Bible Dictionary [2]

("worthlessness": or "recklessness, lawlessness".) Not strictly a proper name, but used so by personification. Βeli means "without" and Ya'Al means "usefulness," i.e. "good for nothing". "A man of Belial" is a worthless, lawless fellow ( Deuteronomy 13:13;  Judges 19:22;  1 Samuel 2:12). Latterly "Rake" ("vain fellows" ( 2 Samuel 6:20, Harekim ), and "Fool" were used instead:  Matthew 5:22. Νabal ("fool") is called "man of Belial" ( 1 Samuel 25:25.) In the New Testament, "Beliar" is the form in some oldest manuscripts ( 2 Corinthians 6:15.) As Satan is opposed to God, Antichrist to Christ, so Belial standing here in contrast to Christ must denote all anti-Christian pollutions personified.

Hawker's Poor Man's Concordance And Dictionary [3]

This is an Hebrew word, signifying somewhat evil. Hence, in Scripture, it is not unfrequently applied to wicked persons. Moses, when charging Israel not to follow vain and ungodly men, calls them sons of Belial. ( Deuteronomy 13:13) The same by Hannah. ( 1 Samuel 1:16) So Abigail to David. ( 1 Samuel 25:25) In the language of the New Testament, Belial is another name for Satan. "What concord (saith Paul) hath Christ with Belial?" ( 2 Corinthians 6:15)

People's Dictionary of the Bible [4]

Belial ( Bç'Li-Al ), Worthlessness, hence Lawlessness, Wickedness. This word is properly applied by the sacred writers to such lewd, profligate, and vile persons, as seem to regard neither God nor man.  Deuteronomy 13:13, A. V., but "base fellows," R. V.  Judges 19:22;  1 Samuel 2:12. In the New Testament, "Belial" is used as an appellation of Satan, the power or lord of evil: "What concord hath Christ with Belial," the prince of licentiousness and corruption?  2 Corinthians 6:15.

Watson's Biblical & Theological Dictionary [5]

The phrase, "sons of Belial," signifies wicked, worthless men. It was given to the inhabitants of Gibeah, who abused the Levite's wife,   Judges 19:22; and to Hophni and Phineas, the wicked and profane sons of Eli.  1 Samuel 2:12 . In later times the name Belial denoted the devil: "What concord hath Christ with Belial?"

 2 Corinthians 6:15; for as the word literally imports "one who will do no one good," the positive sense of a doer of evil was applied to Satan, who is the author of evil, and, eminently, "the Evil One."

Morrish Bible Dictionary [6]

The Hebrew word signifies 'worthless, lawless,' and is not a proper name, but is used as a personification of evil; thus we have 'son of Belial, daughter of Belial,' etc.  Deuteronomy 13:13;  Judges 19:22;  1 Samuel 1:16;  1 Samuel 25:17,25; etc. In the N.T. it is put in contradistinction to Christ as if it meant Satan,  2 Corinthians 6:15 : it is there βελίαρ.

Smith's Bible Dictionary [7]

Be'lial. The meaning of this word as found in the Scriptures is Worthlessness , and hence Reckless, Lawlessness. The expression, Son or Man Of Belial , must be understood as meaning simply A Worthless, Lawless Fellow. The term as used in  2 Corinthians 6:15, is generally understood as an appellative of Satan, as the personification of all that was bad.

Easton's Bible Dictionary [8]

 Deuteronomy 13:13 2 Corinthians 6:15 Deuteronomy 15:9 Psalm 41:8  Proverbs 6:12 Judges 19:22 20:13 1 Samuel 1:16 2:12

Holman Bible Dictionary [9]

 Deuteronomy 13:13 Nahum 1:15

In the New Testament the word occurs one time ( 2 Corinthians 6:15 ). There Paul the apostle declared the mutual irreconcilability of Christ and Belial, who thus appears to be equated with Satan. See Satan; Antichrist .

American Tract Society Bible Dictionary [10]

Worthlessness, always so used in a moral sense. A man or son of Belial is a wicked, worthless man; one resolved to endure no subjection; a rebel; a disobedient, uncontrollable fellow,  Judges 19:22   1 Samuel 2:12 . In later writings, Belial is put for the power or lord of evil, Satan,  2 Corinthians 6:15 .

King James Dictionary [11]

BE'LIAL, n. As a noun, unprofitableness wickedness. As an adjective, worthless wicked. In a collective sense, wicked men.

Webster's Dictionary [12]

(n.) An evil spirit; a wicked and unprincipled person; the personification of evil.

International Standard Bible Encyclopedia [13]

bē´li - al , bēl´yal ( בּליּעל , belı̄ya‛al  ; Βελίαρ , Belı́ar ): This name, occurring very frequently in the Old Testament, has the sense of "worthlessness" (compare  2 Samuel 23:6 margin); accordingly in such phrases as "sons of Belial" (  Judges 20:13;  1 Samuel 10:27 , etc.), "men of Belial" ( 1 Samuel 30:22;  1 Kings 21:13 , etc.), which the English Revised Version usually retains, the American Standard Revised Version more correctly renders, "base fellows" (so "daughter of Belial"  1 Samuel 1:16 , "wicked woman"). There is here no suggestion a proper name. Afterward, however, "Belial" became a proper name for Satan, or for Antichrist (Thus frequently in the Jewish Apocalyptic writings, e.g. in Xii the Priestly Code (P), Book Jubilees, Asc Isa, Sib Or). In this sense Paul used the word in  2 Corinthians 6:15 , "What concord hath Christ with Belial?" ( Beliar ). Bousset thinks that Paul's "man of sin" in  2 Thessalonians 2:3 , where some authorities read "man of lawlessness," is a translation of this term. The sense at least is similar. See Antichrist; Man Of Sin .

The Nuttall Encyclopedia [14]

Properly a good-for-nothing, a child of worthlessness; an incarnation of iniquity and son of perdition, and the name in the Bible for the children of such.