1. The sacramental nature of the Church.
It is common to speak of the "mystery of the Church". "Mystery" in a religious sense does not imply something closed and inaccessible, but rather a reality so deep that we can always discover more to its meaning without ever exhausting it. The Church is more than she appears, and the key to grasping her full reality is faith; "it is only 'with the eyes of faith' that one can see her in her visible reality and at the same time in her spiritual reality as bearer of divine life" (CCC 770).
The Church is the fulfilment of the design of God the Father "to raise up men to share in his own divine life" (LG 2). It is the Kingdom of God which Christ inagurates with his Incarnation, manifests with his words and actions, and whose elements - sacraments, primacy, apostolic college, etc. - he institutes during his life here on earth.
The opening paragraph of Lumen Gentium says that "the Church, in Christ, is in the nature of sacrament..."; it is in other words a sign and a means of grace. The logic of the Church is the logic of the Incarnation of which, in her visible structured institution, she becomes in effect a sacramental prolongation.
Christians believe that Jesus, God become Man, is the Savior of mankind: of each individual person ("there is salvation in no one else": Acts 4:12). How does his saving work reach us? Prayer is the most immediate form of contact open to everyone, everywhere. Is it possible, outside prayer, for a person to have real, living and saving contact with Christ - such for instance as his own contemporaries had? One feels a natural envy for those who lived in Palestine two thousand years ago, with their opportunity of meeting Jesus in the flesh, of being taught and healed directly by him. If only we had had been given the privilege of living in his times; or if He had chosen to be present in ours - so that we too could meet him. We can! "In order to make this 'encounter' with Christ possible, God willed his Church" (Veritatis Splendor, 7). The Church "wishes to serve this single end: that each person may be able to find Christ, in order that Christ may walk with each person the path of life" (Redemptor Hominis, 13).
Jesus Christ came to save us by his sacrifice on the Cross and to lead us, become saints, to heaven. He saves and sanctifies us through his teaching ("I am the way and the truth": Jn 14:16); through his sacraments ("I came that they may have life": Jn 10:10; "he who eats me will live because of me": Jn 6:57); and through the expressions of his will (it is "he who does the will of my Father" who will enter the kingdom of heaven (Mt 7:21); "He who has my commandments and keeps them, he it is who loves me" (Jn 14:21)). He has in a very particular way entrusted his doctrine and sacraments and authority to his Church: "All authority on heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you; and lo, I am with you always, to the close of the age" (Mt 28:18-20).
So, the Church is the continuation of the presence and work of Christ: "the Church is one with Christ" (CCC 795). Faith in the Church is the natural consequence of faith in Jesus Christ.
2. Origin. One can distinguish different moments in the founding of the Church. Its first solemn announcement, when Peter is chosen to be the rock on which is laid its foundation (Mt. 16:18): "On the rock of this faith confessed by St. Peter, Christ built his Church" (CCC 424). Then there was the commission given to the body of the Apostles collegially after Our Lord's Resurrection: "Go therefore and make disciples of all nations... I am with you always" (Mt 28:19-20). And finally on Pentecost Sunday there came the external birth of the Church - beginning to startle the world with a forceful call to repentance, so as to receive forgiveness and salvation (Acts 2:1-4; 11; 37-40). Not only this "birth" of the Church, but her continuing life-giving existence, is considered to be in a particular sense the work of the Holy Spirit (CCC 737). "The Church is the place where the Spirit flourishes" (CCC 749).
3. Mission and activity. The work of the Church in spreading the spirit of the Gospel has always had a powerful effect on human society with her call (the Commandments, the Beatitudes...) to live justice, mutual understanding, forgiveness and peace. This however is a side effect of the Church's mission which cannot be reduced to that of a welfare or humanitarian institution, or to one just concerned with defending and promoting human dignity and rights in this world. The essential mission of the Church is not political or social: "Christ did not bequeath to the Church a mission in the political, economic, or social order; the purpose he assigned her was a religious one" (GS 42; cf. CCC 549): to sanctify, teach and guide people on the way to heaven.
In her identification with Jesus Christ and his messianic work, the Church continues "his threefold office of priest, prophet and king" (CCC 436). Jesus is Priest (Heb 7-8; I Tim 2:5; CCC 1544); he is Teacher (which is the root meaning of prophet), and he is King (cf. Jn 18:36-37; CCC 664). The Church is similarly characterized as having a triple mission or "munus": "priestly", "prophetic" and "kingly" (CCC 888-896).
That these missions are central to understanding the Church is exemplified by the structure given to the 1983 Code of Canon Law (described by Pope John Paul II as "the last document of the Second Vatican Council": AAS 76 (1984) 644). In a complete departure from the previous Code, the new Code configures the laws of the Church according to the Teaching Mission or Office - Munus Docendi - (Book III), the Sanctifying Mission or Office - Munus Sanctificandi - (Book IV), and the mission of ruling - Munus Regendi - (Book II, Part II; Books VI and VII).
While the laity do not exercise the triple mission of Christ within the Church with full ministerial power (for which a special sacramental ordination is needed; cf. CCC 875), their peculiar Christ-given mission is in a certain sense even more challenging. It is - on the basis of their sharing fully in the universal call to holiness (LG Ch. V) - to lead, teach and sanctify, not the Church but the world, doing so "from within", in the words of Lumen Gentium (31; cf. CCC 897ss). Excessive concern with gaining access to positions of ecclesiastical "power" reveals not only a poor understanding of the service nature of Church authority, but also a failure to grasp the proper role and mission of the laity: to make Christ and his saving truth and grace present, known and attractive in the world. Absorption with 'who holds power' in the Church suggests an inward-looking attitude, little awareness of the force and appeal of the Gospel, and a lack of concern for a world in need of salvation.
4. Structure. The Church is a free community. No one is forced to belong to the Church, even though she is open - and necessary - to all. One belongs because of God's call, but also because of one's own free response. The Church is a free community too because only within it does one find the fullness of that Truth which "makes us free" (cf. Jn 8:32). There is a fundamental equality in this community of redeemed persons, all likewise raised to the unique status of being children of God (CCC 683). Along with this equal dignity and vocation within the Church, there is also, as in any society, a variety of functions.
Following the principle of the Incarnation, the Church is both human and divine. "The Church is both visible and spiritual, a hierarchical society and the Mystical Body of Christ. She is one, yet formed of two components, human and divine. That is her mystery, which only faith can accept" (CCC 779). The visible structure of the Church consists not so much in buildings as in persons, institutions and actions.
The Church has a constitution given by her Founder. The Church is not a democracy - in the sense of an institution where authority originates with the people; authority comes rather from above. The Church, by the will of God, is hierarchically structured (CCC 874ff). Our Lord sent the Apostles to teach and rule (Mt. 28: 18-20; Lk 10:16). Along with the Pope, the bishops are the only teachers constituted by divine right. The bishops' authority comes from God (they are not delegates of the clergy or the people, nor for that matter of the Pope); but the choice of each bishop pertains to the Pope. Their authority is not unlimited; but the limitations come not from 'below', but from 'above', from the nature of their mission and office (Mt 16:18; 18:18).
Authority in the Church is both to be exercised and obeyed. However it is very different in its nature and in the mode of its exercise to authority in secular societies. It is important to note two peculiar characteristics of church authority: it is sacred, and it is a work of service.
Authority in the Church is sacred - precisely inasmuch as it derives directly from Christ, and not through any democratic commission. "No one can give himself the mandate and the mission to proclaim the Gospel. The one sent by the Lord does not speak and act on his own authority, but by virtue of Christ's authority; not as a member of the community, but speaking to it in the name of Christ. No one can bestow grace on himself; it must be given and offered. This fact presupposes ministers of grace, authorized and empowered by Christ" (CCC 875).
This is why we speak of "hier-archy" which, in its Greek origin, means "sacred power" - "which is none other than that of Christ" (CCC 1551). It takes faith to keep the sacredness of authority before one's mind: just as with the Holy Sacrament (without faith one sees no more than the natural substance of bread). Authority in the Church is sacred also in that it has a special sanctifying effect, when accepted out of supernatural motives.
Authority in the Church is a work of service (LG 24; CCC 876). "It is entirely related to Christ and to men" (CCC 1551). It is first of all service towards Christ, carrying on his mission. Those in authority in Church must obey God before anything or anyone else (cf. Acts 5:29), and devote themselves to the fulfilment of his will. Church authority is also service of the People, facilitating their way to - and their return to - Christ. Therefore the structures in Church are not power structures, but are geared to "diakonia" and ministry - both words that literally mean service. Jesus said of himself that he "came not to be served but to serve" (Mt 20:28).
St. Thomas Aquinas teaches that "although the Church is supported by God's gift and authority, nevertheless insofar as it is a gathering of men, in its actions some element of human imperfection appears that is not divine" (Sent. IV, d. 41, q. 1, art. 5 ad 1). The Apostles too had their defects, which were used by God to sanctify both them and those in regard to whom they exercised the missions given them by Christ.
We have a guarantee that Christ's Truth is behind the solemn exercise of the Church's Teaching Office (cf. Infallibility). It would be a mistake to look for the same guarantee in relation to the Ruling Office. Issues of truth are not normally involved in questions of Church discipline or government (issues of justice could be; church law provides means for seeking redress, if this is in fact so; see Ecclesial Rights). The presence of the Holy Spirit is nevertheless guaranteed to the Church also in her government. But this does not imply that each measure of government or discipline will always be exercised with perfect prudence. The guarantee we have is rather that Christ's Will (as distinct, if one wishes, from his Truth) is behind measures of government, when exercised in catholic communion; and the further guarantee that whoever accepts such measures in faith and responds to them, is in fact doing what God wants ("he who listens to you, listens to me": Lk 10:16). Behind church law or authoritative decisions which seem hard, the Catholic who takes Jesus seriously will often - rather than protest - choose to discover and accept the cross; and so can be sure of following close behind Christ (cf. Mk 8:34).
It should be clear that the nature of the Church can only be properly determined and appreciated by trying to see what Christ intended to do, and actually did; not by testing what we see against our standards or ideals of human societies. No human society offers salvation, as the Church does; salvation in the Church however is offered on Christ's conditions, not on ours.
5. A means of grace
"The gathering together of the Church is, as it were, God's reaction to the chaos provoked by sin" (CCC 761). She exists not only to save us from the dispersion of sin, but to 'gather into one the scattered children of God' (cf. Jn 11:58); i.e. to raise us to the heights of sanctity, to "the hope of sharing the glory of God" (Rom 5:2) and of attaining "the glorious liberty of the children of God" (Rom 8:21). "The Church, united to Christ, is sanctified by him; by means of him and in him it also becomes sanctifying", remembering that "No one can bestow grace on himself; it must be given and offered" (CCC 824; 875).
From this it follows that the natural attitude of a Christian toward the Church should be one of gratitude and love: for her teaching, guidance, goodness, richness, sacraments, Saints... Our love for the Church should produce in us an attitude of grateful reverence filled with respect. "Let us love the Lord our God; let us love his Church: the Lord as our Father, the Church as our Mother" (St. Augustine, Enarr. in Psal. 87, 2, 14).
To criticise the Church is not natural, just as it is not natural to criticise one's mother or one's family. One prays for the Church; one is proud of the Church. If we love the Church, we will want to bring others to her, helping them, if necessary, overcome the prejudices they may have acquired. Our love for the Church is precisely a condition for drawing them to Christ, present in the Church with the fullness of his saving and sanctifying power.
In the end one's ecclesiology is an even better test of one's faith than one's christology. For it provides the critical proof of belief in the continuing presence and action, in the world and throughout time, of our Savior Jesus Christ, God and Man.