Bible Dictionaries
Must

an impersonal verb, signifying "it is necessary" or "one must," "one ought," is found most frequently in the Gospels, Acts and the Apocalypse, and is used (a) of a necessity lying in the nature of the case e.g., John 3:30; 2 Timothy 2:6; (b) of necessity brought about by circumstances, e.g., Matthew 26:35 , RV, "must," AV, "should;" John 4:4; Acts 27:21 , "should;" 2 Corinthians 11:30; in the case of Christ, by reason of the Father's will, e.g., Luke 2:49; 19:5; (c) of necessity as to what is required that something may be brought about, e.g., Luke 12:12 , "ought;" John 3:7; Acts 9:6; 1 Corinthians 11:19; Hebrews 9:26; (d) of a necessity of law, duty, equity, e.g., Matthew 18:33 , "shouldest;" Matthew 23:23 , "ought;" Luke 15:32 , "it was meet;" Acts 15:5 , "it is needful" (RV); Romans 1:27 , RV, "was due," AV, "was meet" (of a recompense due by the law of God); frequently requiring the rendering "ought," e.g., Romans 8:26; 12:3; 1 Corinthians 8:2; (e) of necessity arising from the determinate will and counsel of God, e.g., Matthew 17:10; 24:6; 26:54; 1 Corinthians 15:53 , especially regarding the salvation of men through the death, resurrection and ascension of Christ, e.g., John 3:14; Acts 3:21; 4:12 . See BEHOVE , No. 2 (where see the differences in the meanings of synonymous words), MEET , NEED , NEEDFUL , OUGHT , SHOULD.