Jesus came incarnate in the flesh as the fulfillment of the Father's desire to be near to those He loves.   Prior to His departure, Christ left us with the Eucharist as the mystical way in which He made good His promise to be with us until the end of the age [Matthew  28:20].

But what is the Eucharist?  Definitions are always lacking. But let's give this explanation as a start. The Eucharist is a sacrificial offering commemorating the grace of salvation through the forgiveness of sin to those who partake in faith. The substance of the bread and the wine is the body and the blood of Christ present in our midst.  However, we do not attempt to explain, but we firmly hold to the early church's statement that Christ is present and it is a Holy Mystery [John 6:50-58].

We might now ask with good reason if Christ's death and resurrection once and for all paid the penalty for man's sin, why does the Church continue to offer the Eucharist in the Mass? Salvation promised and earned for us is conditional. It is contingent upon our acceptance of God's grace, expressed through Christ, and our choosing to be saved and live a lifestyle that demonstrates our understanding of what life in Christ really means.   We were not originally present during Christ's passion.   We need to be reminded of what God has done for us and in our remembrance when the past becomes part of the present and the present becomes part of the past event, our liturgical reenactment of the event makes it a reality for us.

Jesus offers His Body and Blood.  His death brings us life, just as the blood of the lamb saved the Hebrews. Washed in the Blood of the Lamb, we are cleansed of our sins [Hebrews  9:14], and made alive in God's design for our salvation.   Receiving the body of Christ makes each of us living parts in the Body of Christ, the Church. We partake in obedience to Christ's command; it’s not an option.   It is a command to remember Him in this way.   If we constantly fail to remember Jesus and if we fail to renew ourselves with His sacramental meal, it will result in our ceasing to walk as Christians and may even turn our hearts away from God.   We will choose to no longer hear His words of love, no longer receive His Body and Blood by faith, and choose not to live in continued fellowship and intimacy with Him, and no longer be challenged or inspired to love one another as He commanded us to do.