168. Who belongs to the Catholic Church?All human beings in various ways belong to or are ordered to the Catholic unity of the people of God. Fully incorporated into the Catholic Church are those who, possessing the Spirit of Christ, are joined to the Church by the bonds of the profession of faith, the sacraments, ecclesiastical government and communion. The baptized who do not enjoy full Catholic unity are in a certain, although imperfect, communion with the Catholic Church.
Further reading: CCC 836-838169. What is the relationship of the Catholic Church with the Jewish people?
The Catholic Church recognizes a particular link with the Jewish people in the fact that God chose them before all others to receive his Word. To the Jewish people belong "the sonship, the glory, the covenants, the giving of the law, the worship, the promises, and the patriarchs; and of their race, according to the flesh, is the Christ" (Romans 9:4, 5). The Jewish faith, unlike other non-Christian religions, is already a response to the revelation of God in the Old Covenant.
Further reading: CCC 839-840