Jesus Christ is one divine Person with two natures: He is fully God and fully man. In the Old Testament, Moses asked God, "Show me your glory" (Exodus 33:18). God replied that no one could see His face and live. Therefore, God revealed Himself to Moses only in a limited way, expressing this through the image of allowing Moses to see His "back," signifying that God's full glory cannot be seen by human beings in this life.
In the fullness of time, the eternal Son of God became man without ceasing to be God. Jesus Christ humbled Himself by taking on our human nature while remaining fully divine. The Father, the Son, and the Holy Spirit are three distinct Persons united in one God, “The Most Holy Trinity”.
Before His Passion, Jesus gave humanity His greatest sacramental gift: the Holy Eucharist. At every Mass, through the ministry of the ordained priest, who acts in persona Christi ("in the person of Christ"), and by the power of the Holy Spirit, the bread and wine are transformed by transubstantiation into the true Body and Blood of Christ. Although the appearances of bread and wine remain, Christ is truly, really, and substantially present: “Body, Blood, Soul, and Divinity.”
When we receive Holy Communion worthily, we receive Christ Himself. The Eucharist unites us more deeply with Him, strengthens us with His divine life, and unites us with all the members of His Mystical Body, the Church. It is truly the most precious gift we can receive in this life, for in the Eucharist, Jesus gives us not merely a symbol of Himself, but His very Self.