<P> The Church considers the law of clerical celibacy to be not a doctrine, but a discipline . Exceptions are sometimes made, especially in the case of married Protestant clergymen who convert to the Catholic Church, and the discipline could in theory be changed for all ordinations to the priesthood . </P> <P> Theologically, the Church teaches that priesthood is a ministry conformed to the life and work of Jesus Christ . Priests as sacramental ministers act in persona Christi, that is in the person of Christ . Thus the life of the priest conforms, the Church believes, to the chastity of Christ himself . The sacrifice of married life is for the "sake of the Kingdom" (Luke 18: 28--30, Matthew 19: 27--30), and to follow the example of Jesus Christ in being "married" to the Church, viewed by Catholicism and many Christian traditions as the "Bride of Christ" (following Ephesians 5: 25 - 33 and Revelation 21: 9, together with the spousal imagery at Mark 2: 19 - 20; cf . Matthew 9: 14 - 15). </P> <P> Cardinal Joseph Ratzinger (later Pope Benedict XVI) in Salt of the Earth saw this practice as based on Jesus' words in Matthew 19: 12: "Some are eunuchs because they were born that way; others were made that way by men; and others have renounced marriage because of the kingdom of heaven . The one who can accept this should accept it ." He linked this celibacy "because of the kingdom of heaven" with God's choice to confer the Old Testament priesthood on a specific tribe, that of Levi, which unlike the other tribes received no land from God, but which had "God himself as its inheritance" (Numbers 1: 48--53). </P> <P> Paul, within a context of having "no command from the Lord" (1 Cor 7: 25), recommends celibacy, but acknowledges that it is not God's gift to all within the church: "For I wish that all men were even as I myself . But each one has his own gift from God, one in this manner and another in that . But I say to the unmarried and to the widows: It is good for them if they remain even as I am,...I want you to be without care . He who is unmarried cares for the things of the Lord--how he may please the Lord . But he who is married cares about the things of the world--how he may please his wife . There is a difference between a wife and a virgin . The unmarried woman cares about the things of the Lord, that she may be holy both in body and in spirit . But she who is married cares about the things of the world--how she may please her husband . And this I say for your own profit, not that I may put a leash on you, but for what is proper, and that you may serve the Lord without distraction" (1 Corinthians 7: 7--8, 7: 32--35). Paul's recommendation of celibacy could be explained by his expectation that the end was near: "The appointed time has grown short...Let those who have wives live as if they have none...For the present form of this world is passing away" (1 Corinthians 7: 29 - 31). This would be consistent with Jesus' expectation of an imminent coming of the kingdom, in continuity with the Baptist (Mark 9: 1; 13: 30, 32). </P>

When did it become illegal for priests to marry