This word in both English and Greek is a transliteration from the Hebrew ʼa·menʹ. The meaning is “so be it,” or “surely.” The Hebrew root word from which it is drawn (ʼa·manʹ) means “be faithful; be trustworthy.”

In the Hebrew Scriptures the word is used as a solemn expression to obligate oneself legally to an oath or covenant and its consequences (Nu 5:22; De 27:15-26; Ne 5:13), also as a solemn expression to subscribe to an expressed prayer (1Ch 16:36), to an expression of praise (Ne 8:6), or to an expressed purpose (1Ki 1:36; Jer 11:5). Each of the first four books, or collections, of the Psalms concludes with this expression, perhaps indicating that it was customary for the congregation of Israel to join in at the end of the song or psalm with an “Amen.”​—Ps 41:13; 72:19; 89:52; 106:48.

The Hebrew word ʼa·manʹ is applied to Jehovah as “the faithful God” (De 7:9; Isa 49:7) and describes his reminders and promises as “trustworthy” and “faithful.” (Ps 19:7; 89:28, 37) In the Christian Greek Scriptures the title “Amen” is applied to Christ Jesus as “the faithful and true witness.” (Re 3:14) Jesus made singular use of the expression in his preaching and teaching, using it very often to preface a statement of fact, a promise, or a prophecy, thereby emphasizing the absolute truthfulness and reliability of what he said. (Mt 5:18; 6:2, 5, 16; 24:34) In these cases the Greek word (a·menʹ) is translated as “truly” (KJ, “verily”) or, when doubled, as throughout the book of John, “most truly.” (Joh 1:51) Jesus’ use of “amen” in this way is said to be unique in sacred literature, and it was consistent with his divinely given authority.​—Mt 7:29.

However, as Paul shows at 2 Corinthians 1:19, 20, the title “Amen” applies to Jesus not merely as a truth speaker or as a true prophet and spokesman of God but also as the one in whom all of God’s promises find fulfillment. His course of faithfulness and obedience even to a sacrificial death confirms and makes possible the bringing to reality of all the promises and declarations of God’s purpose. He was the living Truth of those revelations of God’s purpose, the things to which God had sworn.​—Compare Joh 1:14, 17; 14:6; 18:37.

 The expression “Amen” is used many times in letters, especially those of Paul, when the writer has expressed some form of praise to God (Ro 1:25; 16:27; Eph 3:21; 1Pe 4:11) or expresses the wish that God’s favor be manifested in some manner toward the recipients of the letter. (Ro 15:33; Heb 13:20, 21) It is also used where the writer earnestly subscribes to what is expressed.​—Re 1:7; 22:20.

The prayer expressed at 1 Chronicles 16:36 and those contained in the Psalms (41:13; 72:19; 89:52; 106:48), as well as the expressions contained in the canonical letters, all indicate the correctness of the use of “Amen” at the close of prayers. It is true that not all the prayers recorded show such conclusion, such as David’s closing prayer for Solomon (1Ch 29:19) or Solomon’s dedication prayer at the inauguration of the temple (1Ki 8:53-61), although such expression may well have been made. (Note 1Ch 29:20.) Similarly, its use is not recorded in Jesus’ prayers (Mt 26:39, 42; Joh 17:1-26) or in the prayer of the disciples at Acts 4:24-30. However, the weight of the prior evidence presented strongly indicates the rightness of the use of “Amen” as a conclusion to prayer, and Paul’s statement at 1 Corinthians 14:16 in particular shows that it was customary for those in Christian assembly to join in the Amen to a prayer. Additionally, the examples of those in heaven, recorded at Revelation 5:13, 14; 7:10-12; and 19:1-4, all give support to its use in subscribing to prayers or solemn statements and thereby, through the use of this one word, expressing the confidence, strong approval, and earnest hope that is in their hearts.