Does not St. Peter say that all Christians are a holy priesthood?

The Catholic Answers

Yes, and in a certain sense it is true. Baptism implies a certain consecration to God, and the obligation to offer the sacrifice of praise by a sincere life of prayer and of good works. He points out that, as the Jews were a chosen race, so the baptized are the chosen race to day. But the Jews had in addition specially chosen men consecrated as Priests among themselves. Thus, whilst Christians are a chosen race now, offering the sacrifice of praise and of a pure life to God, certain men must be chosen from among them to offer the special Sacrifice of Christ’s Body and Blood, and to forgive sins. In this sense not all Christians are Priests.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty