(en Kurio): A favorite Pauline expression, denoting that intimate union and fellowship of the Christian with the Lord Jesus Christ which supplies the basis of all Christian relations and conduct, and the distinctive element in which the Christian life has its specific character. Compare the synonymous Pauline phrases, "in Christ," "in Christ Jesus," and the Johannine expressions, "being in Christ," "abiding in Christ." "In the Lord" denotes: (1) the motive, quality, or character of a Christian duty or virtue, as based on union with Christ, e.g. "Free to be married to whom she will; only in the Lord" (1Co 7:39), i.e. provided the marriage be consistent with the Christian life. Compare 1Co 15:58; Php 3:1; 4:1,2,4,10; Eph 6:1,10; Col 3:18, etc.; (2) the ground of Christian unity, fellowship, and brotherly salutation, e.g. Ro 16:2,8,22; 1Co 16:19; Col 4:7; (3) it is often practically synonymous with "Christian" (noun or adjective), "as Christians" or "as a Christian," e.g. "Salute them of the household of Narcissus, that are in the Lord," i.e. that are Christians (Ro 16:11); "I.... the prisoner in the Lord," i.e. the Christian prisoner (Eph 4:1); compare Ro 16:13; 1Co 9:1,2; Eph 6:21 ("faithful minister in the Lord" = faithful Christian minister); Col 4:17 (see Grimm-Thayer, Lex. of New Testament, en, I, 6).
  D. Miall Edwards