Hebrews 5
(Heb 5, 1-3) Every high priest is taken from among menEvery high priest is taken from among men and made their representative before God, to offer gifts and sacrifices for sins. He is able to deal patiently with the ignorant and erring, for he himself is beset by weakness and so, for this reason, must make sin offerings for himself as well as for the people.
(CCC 1585) The grace of the Holy Spirit proper to this sacrament is configuration to Christ as Priest, Teacher, and Pastor, of whom the ordained is made a minister. (CCC 1581) This sacrament configures the recipient to Christ by a special grace of the Holy Spirit, so that he may serve as Christ's instrument for his Church. By ordination one is enabled to act as a representative of Christ, Head of the Church, in his triple office of priest, prophet, and king. (CCC 1582) As in the case of Baptism and Confirmation this share in Christ's office is granted once for all. The sacrament of Holy Orders, like the other two, confers an indelible spiritual character and cannot be repeated or conferred temporarily (Cf. Council of Trent: 1 DS 1767; LG 21; 28; 29; PO 2). (CCC 1583) It is true that someone validly ordained can, for a just reason, be discharged from the obligations and functions linked to ordination, or can be forbidden to exercise them; but he cannot become a layman again in the strict sense (Cf. CIC, cann. 290-293; 1336 SS 1 3^0, 5^0, 1338 SS 2; Council of Trent: DS 1774), because the character imprinted by ordination is for ever. The vocation and mission received on the day of his ordination mark him permanently.
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