From Pope St. John Paul II’s Apostolic Exhortation Reconciliatio et Pænitentia (1984):
Last, I particularly wish to speak of one final consideration, one which concerns all of us priests, who are the ministers of the sacrament of penance.193 The priest’s celebration of the eucharist and administration of the other sacraments, his pastoral zeal, his relationship with the faithful his communion with his brother priests, his collaboration with his bishop, his life of prayer—in a word, the whole of his priestly existence, suffers an inexorable decline if by negligence or for some other reason he fails to receive the sacrament of penance at regular intervals and in a spirit of genuine faith and devotion. If a priest were no longer to go to confession or properly confess his sins, his priestly being and his priestly action would feel its effects very soon and this would also be noticed by the community of which he was the pastor.
But I also add that even in order to be a good and effective minister of penance the priest needs to have recourse to the source of grace and holiness present in this sacrament. We priests, on the basis of our personal experience, can certainly say that the more careful we are to receive the sacrament of penance and to approach it frequently and with good dispositions, the better we fulfill our own ministry as confessors and ensure that our penitents benefit from it. And on the other hand, this ministry would lose much of its effectiveness if in some way we were to stop being good penitents. Such is the internal logic of this great sacrament. It invites all of us priests of Christ to pay renewed attention to our personal confession.
Personal experience in its turn becomes and must become today an incentive for the diligent, regular, patient and fervent exercise of the sacred ministry of penance, to which we are committed by the very fact of our priesthood and our vocation as pastors and servants of our brothers and sisters. Also with this present exhortation I therefore address an earnest invitation to all the priests of the world, especially to my brothers in the episcopacy and to pastors of souls, an invitation to make every effort to encourage the faithful to make use of this sacrament. I urge them to use all possible and suitable means to ensure that the greatest possible number of our brothers and sisters receive the “grace that has been given to us” through penance for the reconciliation of every soul and of the whole world with God in Christ.
193 Cf Presbyterorum Ordinis, 18.
— Reconciliatio et Pænitentia 31