But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth.
But if I tarry long - before coming.
That - i:e., I write (1 Timothy 3:14) "that thou mayest know," etc.
Behave thyself - in directing the church at Ephesus (1 Timothy 4:11).
The house of God - the Old Testament (Numbers 12:7; Hosea 8:1) and the New Testament Church (1 Corinthians 3:16; Ephesians 2:20; Ephesians 2:22; Hebrews 3:2; Hebrews 3:5-6; Hebrews 10:21; 1 Peter 4:17).
Which is - i:e., inasmuch as it is.
The church, х ekkleesia (G1577)] - 'the congregation,' the communion of saints [Hebrew, 'Aleph (')]. The fact that thy sphere of office is, 'the congregation of God' (the ever-living Master of the house, unlike the dead idol Diana, of the Ephesian temple (2 Timothy 2:19-21), is the strongest motive to faithfulness in thy behaviour as president of a department of it. The living God contrasts with the lifeless idol, Diana of Ephesus (1 Thessalonians 1:9). He is the fountain of "truth:" the foundation of our "trust" (1 Timothy 4:10). Labour for a particular church is service to the one great house of God, of which each church is a part, and each Christian a lively stone (1 Peter 2:5). The pillar and ground [ hedraiooma (G1477 ): basis] of the truth - predicated of the Church, not of "the mystery of godliness;" for, after two weighty predicate substantives, "pillar and ground," a third, a weaker predicate, and an adjective, 'confessedly ["without controversy:" homologoumenos] great,' would not come. "Pillar" is used metaphorically of the three apostles on whom, humanly speaking, the Jewish Christian church depended (Galatians 2:9: cf. Revelation 3:12). The Church is "the pillar of the truth," as the continuance (historically) of the truth rests on it: it witnesses to and preserves the Word of truth. He who is of the truth belongs by the very fact to the Church, for He belongs to Christ, its Head (John 18:37, end). Christ is the alone "ground" of the truth in the highest sense (1 Corinthians 3:11). The apostles are 'foundations' in a secondary sense (Ephesians 2:20; Revelation 21:14). The Church rests on the truth as it is in Christ, not the truth on the Church.
But the truth as it is in itself is to be distinguished from the truth as it is acknowledged in the world. The former needs no pillar, but supports itself; the latter needs the Church as its pillar - i:e., its human upholder and preserver under God. The importance of Timothy's commission appears from the excellence of "the house," and this in opposition to the heresies which Paul presciently forewarns him of (1 Timothy 4:1; Matthew 16:18; Matthew 28:20). Rome falsely claims the promise. But it is not historical descent that constitutes a church, but this only, that it upholds the truth. The absence of this unchurches Rome. The "pillar" is the intermediate, the "ground" (cf. "foundation," 2 Timothy 2:19) the ultimate stay of the buildings. It is no objection that, having called the Church "the house of God," he now calls it the "pillar;" for the literal word "church" immediately precedes the new metaphors. The Church, before regarded as the habitation of God, is now, from a different point of view, regarded as the pillar upholding the truth.