Jesus Christ was incarnated to fulfill a threefold mission: to be Priest, to be Prophet, and to be King (CCC 783). The Liturgy is our participation in that mission. We serve as King through charity. We serve as prophet by proclaiming the truth of the Church. We serve as Priest by uniting ourselves to the sacrifice of Christ in worship.
Jesus is the perfect high priest because “he holds his priesthood permanently, because he continues for ever. Consequently he is able for all time to save those who draw near to God through him, since he always lives to make intercession for them” (RSV, Hebrews 7:24-25). Fundamentally, worship is an act of sacrifice. We give up something we value for God. Our high priest makes the perfect offering of Himself. Jesus is both the Priest who offers the sacrifice and He is the offering. It is only the perfect sacrifice of Himself that can make atonement for sin. We unite ourselves in this sacrifice to make a perfect act of worship!
Christ is the greatest of prophets for he had the greatest claim to truth. He founded his Church and gives us a share in His prophetic ministry. We loudly proclaim the revealed truths of God through our prayers and reading of the inspired word of God. We are called to spread His redeeming message throughout the world and prominently through the rites of Liturgy.
Both our worship and our proclamation participate in the kingly mission of Charity. Christ has dominion over all of creation. Jesus shares His noble ministry with us and it comes with a responsibility to maintain the common good. “Now Christ has communicated this royal power to His disciples that they might be constituted in royal freedom and that by true penance and a holy life they might conquer the reign of sin in themselves. Further, He has shared this power so that serving Christ in their fellow men they might by humility and patience lead their brethren to that King for whom to serve is to reign” (Lumen Gentium par. 36). He constitutes us with Kingly power so we might in turn serve others in the spirit of charity.