23 To them this is the mystery of the newness of Christ, of all that He is and stands for; it is the sum of the highest ideals of the Gospel and of the kingdom; it is a particular manifestation of grace, which springs from the Paschal mystery of the Savior. This is what makes the choice of celibacy desirable and worthwhile to those called by our Lord Jesus. Thus they intend not only to participate in His priestly office, but also to share with Him His very condition of living.
Source: Sacerdotalis Caelibatus (Vatican.va)