Each year on the Friday following the feast of Corpus Christi, the Church looks to the Sacred Heart of Jesus. It is on this day that the Church is also encouraged to pray for priests, on what is now called the World Day of Prayer for the Sanctification of Priests.
St. John Paul II instituted this day in 2002 to highlight the importance of praying for priests. The Congregation for the Clergy also noted, "That day was chosen because the feast of the Sacred Heart celebrates God's merciful love, that becomes tangible for priests in the Eucharistic Mystery, which they celebrate daily, and in the sacramental pardon which they administer and receive."
In particular, St. John Paul II explained in a Letter to Priests in 2001 that priests are also in need of the sacraments, especially the sacrament of reconciliation.
Dear priests, let us make regular use of this Sacrament, that the Lord may constantly purify our hearts and make us less unworthy of the mysteries which we celebrate. Since we are called to show forth the face of the Good Shepherd, and therefore to have the heart of Christ himself, we more than others must make our own the Psalmist's ardent cry: "A pure heart create for me, O God, put a steadfast spirit within me" (Ps 51:12). The Sacrament of Reconciliation, essential for every Christian life, is especially a source of support, guidance and healing for the priestly life.
The priest who fully experiences the joy of sacramental reconciliation will find it altogether normal to repeat to his brothers and sisters the words of Paul: "So we are ambassadors for Christ, God making his appeal through us. We beseech you on behalf of Christ, be reconciled to God" (2 Cor 5:20).
Priests are human beings and are often the subject of temptations. St. John Paul II recognized this fact and implored the world to pray for priests on the Solemnity of the Sacred Heart, ensuring that they would remain holy and devoted to God.