The Encountering of Jesus's Presence in the Mass
When we come to Mass, we come to encounter the crucified and risen Jesus, He who will come again. We are told that He is present in the liturgy: in the priest; the Sacraments; Word of God, the scriptures, and in the people of God assembled.
Jesus is present in the priest. This is true, not because the priest is a perfect person—one need only read the news to know this is true; I need only look into the mirror to know this is true. The priest has been configured by sacred ordination to stand, in a common theological expression, in personae Christi capitis (in the person of Christ, the Head). This means that the priest stands in the place of Christ in the liturgical celebration. Note that this is the only context. The priest does not walk down the street or watch TV in the place of Christ (this is where some priests can go off the rails.) In liturgy, the priest acts as the celebrant in the place of Christ in such a way that the priest speaks the words of Christ in the first person— “this is my body”; “this is my blood”; “I absolve you.” Because of this understanding, the Church long ago solved the problem of unworthy priests celebrating the sacraments. The Sacraments work even through priests in sin because it is Christ who acts in the priest and not the priest acting on his own.
Jesus is present in the Scriptures. The scriptures are the inspired Word of God. Jesus is the incarnate Word of God. The scriptures make Him present to us. Not just the Gospels, the whole of the inspired scriptures that we hear at Mass are places that we meet Jesus.
Jesus is present in the Sacraments; He is present when a sacrament is celebrated. He forgives in reconciliation. He joins in marriage. He ordains a priest. He baptizes. He is present in a special way in the Body and Blood of Christ under the form of bread and wine. While in the other sacraments, Christ is there as the sacrament is celebrated, He does not remain in the same way that He does in the Eucharist. After the other sacraments, He may remain in grace, or in effect. In the Eucharist He remains in an abiding real way (not just symbolically!) in the Eucharist.
Jesus is present in the Church gathered. The Church is the People of God, the clergy and laity together (I have seen much that speaks of the People of God as if the pope, bishops, priests, and deacons were not a part—People of God as a counter party to the clergy. This is incorrect, all make up the people of God). He is present when two or three are gathered. This is more clearly seen when the Church gathers for liturgy, especially when the Church in a diocese gathers with their bishop or when a parish gathers with their priest to celebrate the Mass.
The Mass is our time to encounter Christ in a particular way. Think of it in terms of your relationship with your friends or family members. Letters, emails, texts, and phone calls are one way of interacting with them, but that pales in comparison to being with them. So we can relate to Jesus in many ways—especially prayer, but it is in liturgy that we meet Him in person.