Ad Majorem Dei Gloriam (To the Greater Glory of God)
From: Ephesians 2:19-22
Reconciliation of Jews and Gentiles in Christ (Continuation)
 So then you are no longer strangers and sojourners, but you are fellow citizens with the saints and members of the household of God,  built upon the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone,  in whom the whole structure is joined together and grows into a holy temple in the Lord;  in whom you also are built into it for a dwelling place of God in the Spirit.
11-22. What is the significance of the calling of the Gentiles to the Church? Their previous situation, separated from Christ (vv. 11-12), has undergone radical change as a result of the Redemption Christ achieved on the Cross: that action has, on the one hand, brought the two peoples together (made peace between them: vv. 13-15) and, on the other, it has reconciled them with God, whose enemy each was (vv. 16- 18). The Redemption has given rise to the Church, which St Paul here describes as a holy temple built on the foundation of the apostles and prophets (vv. 19-22).
19. After describing the Redemption wrought by Christ and applied in the Church by the Holy Spirit, St Paul arrives at this conclusion: the Gentiles are no longer strangers; they belong to Christ's Church.
In the new Israel (the Church) privileges based on race, culture or nationality cease to apply. No baptized person, be he Jew or Greek, slave or free man, can be regarded as an outsider or stranger in the new people of God. All have proper citizenship papers. The Apostle explains this by using two images: The Church is the city of saints, and God's family or household (cf. 1 Tim 3:15). The two images are complementary: everyone has a family, and everyone is a citizen. In the family context, the members are united by paternal, filial and fraternal links, and love presides; family life has a special privacy. But as a citizen one is acting in a public capacity; public affairs and business must be conducted in a manner that is in keeping with laws designed to ensure that justice is respected. The Church has some of the characteristics of a family, and some of those of a polity (cf. St Thomas Aquinas, "Commentary on Eph, ad loc.").
The head of the Church is Christ himself, and in his Church are assembled the children of God, who are to live as brothers and sisters, united by love. Grace, faith, hope, charity and the action of the Holy Spirit are invisible realities which forge the links bringing together all the members of the Church, which is moreover something very visible, ruled by the successor of Peter and by the other bishops (cf. Vatican II, "Lumen Gentium", 8), and governed by laws--divine and ecclesiastical--which are to be obeyed.
20-22. To better explain the Church, the Apostle links the image of "the household of God" to that of God's temple and "building" (cf. 1 Cor. 3:9). Up to this he has spoken of the Church mainly as the body of Christ (v. 16). This image and that of a building are connected: our Lord said, "Destroy this temple and in three days I will raise it up" (Jn 2:19), and St John goes on to explain that he was speaking "of the temple of his body" (Jn 2:21). If the physical body of Christ is the true temple of God because Christ is the Son of God, the Church can also be seen as God's true temple, because it is the mystical body of Christ.
The Church is the temple of God. "Jesus Christ is, then, the foundation stone of the new temple of God. Rejected, discarded, left to one side, and done to death--then as now--the Father made him and continues to make him the firm immovable basis of the new work of building. This he does through his glorious resurrection [...].
"The new temple, Christ's body, which is spiritual and invisible, is constructed by each and every baptized person on the living cornerstone, Christ, to the degree that they adhere to him and 'grow' in him towards 'the fullness of Christ'. In this temple and by means of it, the 'dwelling place of God in the Spirit', he is glorified, by virtue of the 'holy priesthood' which offers spiritual sacrifices (1 Pet 2:5), and his kingdom is established in the world.
"The apex of the new temple reaches into heaven, while, on earth, Christ, the cornerstone, sustains it by means of the foundation he himself has chosen and laid down--'the apostles and prophets' (Eph 2:20) and their successors, that is, in the first place, the college of bishops and the 'rock', Peter (Mt 16: 18)" (John Paul II, "Homily at Orcasitas, Madrid", 3 November 1981).
Christ Jesus is the stone: this indicates his strength; and he is the cornerstone because in him the two peoples, Jews and Gentiles, are joined together (cf. St Thomas Aquinas, "Commentary on Eph, ad loc".). The Church is founded on this strong, stable bedrock; this cornerstone is what gives it its solidity. St Augustine expresses his faith in the perennial endurance of the Church in these words: "The Church will shake if its foundation shakes, but can Christ shake? As long as Christ does not shake, so shall the Church never weaken until the end of time" ("Enarrationes in Psalmos", 103).
Every faithful Christian, every living stone of this temple of God, must stay fixed on the solid cornerstone of Christ by cooperating in his or her own sanctification. The Church grows "when Christ is, after a manner, built into the souls of men and grows in them, and when souls also are built into Christ and grow in him; so that on this earth of our exile a great temple is daily in course of building, in which the divine majesty receives due and acceptable worship" (Pius XII, "Mediator Dei", 6).