The Catechism in Questions & Answers

414. Were there any references to the spiritual ministry in the Old Testament?

Already in the Old Testament references to the spiritual ministry can be found in the activity of kings, priests, and prophets: the king ruled, the priest mediated the blessing of God, and the prophet proclaimed the will of God. These ministries are references to the spiritual ministry.
Everything that had been established in the ministry of the Old Testament is reflected in Jesus Christ. He is King, Priest, and Prophet all in one.