Each year at the Chrism Mass, celebrated in cathedral churches across the world on the occasion of Holy Thursday, priests come together at the invitation of the diocesan ordinary, their bishop, to concelebrate the Mass with him and, in his presence and that of the lay faithful, renew their priestly promises. There is every reason to believe that many priests make what is often a long journey to the cathedral precisely to renew the commitment to the priesthood first undertaken on the day they were ordained.
The Chrism Mass itself is a unique expression of priestly solidarity between the diocesan bishop and his clergy. It gathers together in the mother church, just once in the year, the diocesan family and is a corporate expression of its unity in its diversity of ministries (ordained and lay).