NOTES for Ti1 3:15
Speaking of the Church, Paul calls it the house of God, the "support and foundation of the truth" (v. 15). For everyone at least superficially familiar with the Yahwistic tradition and, in particular, with Yahwistic worship, this definition was associated with the Jerusalem Temple as the place of God's presence, which sanctified the people and made them a single spiritual whole. Of course, according not to the priestly but to the rabbinic tradition, that same presence also dwelt in sacred gatherings, such as the Passover seder or the Sabbath meal, for example, but they were understood as a continuation of the sacred sacrificial meals of the Temple, with which they were connected not only by unity of faith, but also by unity of sacrifice: consecrated sacrificial meat was present at these meals right up to A.D. 70, until the end of the era of the Second Temple and the cessation of Yahwistic sacrifices.
Paul, however, clearly calls the church assembly the house of God, and this is not surprising: for here, in the apostle's thought, that fullness of the Kingdom became visible and was opened to all who participated, a fullness that usually remained hidden from the world and will be opened to it only on the day of Judgment and the return of the Savior. But this fullness, clearly, is connected no longer with temple worship, but with what the Savior brought into the world (v. 16). The apostle does not accidentally connect the "mystery of godliness" with the path of Christ, which is nothing other than the incarnation of God, step by step opening itself more fully to the world. And this revelation turns out to be inseparable from the revelation of the Kingdom entering the world. It is precisely the breath of the Kingdom, the breath of God, that manifests the fullness of the Messiah's righteousness ("...He justified Himself in spirit," Paul says). Only in the Kingdom, where there is no impassable boundary between spirit and nature, can a man born of an earthly woman show Himself to angels. And only by the Spirit of God is the good news of the birth of the Messiah promised by God proclaimed and received in the world, so that those who seek the Kingdom may hear, believe what they have heard, and follow the One in whom they have placed their trust.
When all this happened, the fullness of God's presence proper to the Kingdom was opened to the world, which the apostle, following traditional usage, calls the "glory" accompanying the Messiah risen from the dead. And the whole path traveled by Christ leads into the Church, into that assembly where He Himself, risen from the dead in order to give the world the Kingdom, becomes the presider. The Kingdom that, according to the apostle's word, becomes the "support and foundation of the truth," embodied in the Church just as the fullness of God was embodied in Jesus Christ Himself.