I Timothy 3:15

But if I tarry long--before coming to thee. that--that is, I write (Ti1 3:14) "that thou mayest know," &c. behave thyself--in directing the Church at Ephesus (Ti1 4:11). the house of God--the Church (Heb 3:2, Heb 3:5-6; Heb 10:21; Pe1 4:17; Co1 3:16, "the temple of God"; Eph 2:22). which is--that is, inasmuch as it is. the church--"the congregation." The fact that the sphere of thy functions is "the congregation of the living God" (who is the ever living Master of the house, Ti2 2:19-21), is the strongest motive to faithfulness in this behavior as president of a department of the house." The living God forms a striking contrast to the lifeless idol, Diana of Ephesus (Th1 1:9). He is the fountain of "truth," and the foundation of our "trust" (Ti1 4:10). Labor directed to a particular Church is service to the one great house of God, of which each particular Church is a part, and each Christian a lively stone (Pe1 2:5). the pillar and ground of the truth--evidently predicated of the Church, not of "the mystery of godliness" (an interpretation not started till the sixteenth century; so BENGEL); for after two weighty predicates, "pillar and ground," and these substantives, the third, a much weaker one, and that an adjective, "confessedly," or "without controversy great," would not come. "Pillar" is so used metaphorically of the three apostles on whom principally the Jewish Christian Church depended (Gal 2:9; compare Rev 3:12). The Church is "the pillar of the truth," as the continued existence (historically) of the truth rests on it; for it supports and preserves the word of truth. He who is of the truth belongs by the very fact to the Church. Christ is the alone ground of the truth in the highest sense (Co1 3:11). The apostles are foundations in a secondary sense (Eph 2:20;…

In this chapter our apostle treats of church-officers. He specifies, I. The qualifications of a person to be admitted to the office of a bishop (Ti1 3:1-7). II. The qualifications of deacons (Ti1 3:8-10), and of their wives (Ti1 3:11), again of the deacons (Ti1 3:12, Ti1 3:13). III. The reasons of his writing to Timothy, whereupon he speaks of the church and the foundation-truth professed therein (Ti1 3:14 to the end).

3:15 household of God: The earliest churches were house churches (Rom 16:5; 1 Cor 16:19; Col 4:15; Phlm 1:2) that reflected the codes of conduct of Greco-Roman households (see study note on 1 Tim 3:4-5). Violating these norms brought disrepute, disgrace, and shame on the entire household and its head. The same is true for the church (cp. Eph 2:19-22; Heb 3:6; 10:21; 1 Pet 4:17). • the church . . . is the pillar and foundation of the truth: This idea may anticipate the transition from the time of the apostles to the period after their deaths (cp. Gal 2:9; Rev 3:12). The church must be active rather than defensive in upholding the truth in the world (cp. 2 Cor 10:3-6).