The next way a person is related to the People of God, is by being a catechumen, enrolled to be brought into the Catholic Church. (Once again, note that the People of God is the Catholic Church.) A catechumen has an explicit desire to enter the Church and is by that fact already “joined” to the Church (congiugitur).
The next way someone can be related to the Church is by being validly baptized though one is not Catholic. All such are “joined” to the Church (coniunctam) by their baptism. The grace that operates in them through the elements of sanctification and truth of their Christian community objectively orients them to the one true Church of Christ, the Catholic Church, that all may be one.
All others, in various ways (Jews, Muslims, theists, and even those who do not have explicit knowledge of God) are “related / ordered” to the Church (ordinatur). God is not remote from any of these, granting them sufficient grace for conversion and salvation. That is, God calls all of these to be converted to the one true faith and abandon everything false. This will entail leaving their religion behind, although not leaving behind the various truths which their religion espouses, such as belief in good moral principles, belief in one creator God, an appreciation of the goodness of being and of human dignity, etc. For Jesus has abrogated the Old Law and established the New Law in its place. Further, he is the final and definitive prophet, and every Christian recognizes as false anyone who proclaims to add to his message in the name of God.
Let us sum up. Only Catholics are members of Christ’s Church. These are either living or dead, but they are all members. For the Church is a visible society. Its boundaries are determined by visible, societal marks. And although these bespeak a certain minimal internal reality – namely, confession of the true faith and acceptance of hierarchical communion – these internal realities are adequately signified in one’s visible activity (“I believe in one God, the Father Almighty”). Thus, true membership does not await a judgment of the internal forum (“I confess for having sinned mortally…”). (However, a priest hearing a confession can inform someone that he has really renounced membership by renouncing one of these criteria of the visible society.) In short, the Church embraces sinners as her own. After all, only one disciple of Christ was without sin – Mary. The Church strives to recover all her own who have fallen into sin for Christ, thus snatching them from the Devil, just as she strives to reach out to those who are not her members, that they may avail themselves of the riches Christ as bestowed upon us through his Bride.
Others are related to the Church in various ways. Catechumens are joined by an explicit desire. Christians are joined by their baptism and, further, their desire to follow Christ wherever he goes. Non-Christians are, in various ways “ordered” to the one true Church, called to join her by following the good inspirations of grace which the Holy Spirit grants them, so that at length they may have life and achieve salvation.
At last we come to the surprising point I noted in Part I. Many canonists – those who study canon law – argue that valid baptism considered as such makes one a member of the Catholic Church. This membership, they add, is not forfeited until the baptized person undertakes some rational act incompatible with that membership. An obvious example of this would be a baptized person who repudiates all faith in God. Another would be a baptized person who repudiates the Catholic Church, or some dogma of Catholic faith, such as the Eucharist. The argument is that some who are baptized are unable to have such acts incompatible with membership. For instance, the infants. In practice, however, such persons are not dealt with as Catholics, since their parents do not intend this for them and since holding such persons to account as the Church does for Catholics (e.g., with regard to canon law, the conditions for valid marriage etc.) would be too complicated and too burdensome for the individual.