Yes...we do this to remember His sacrifice on the Cross. It is not bringing Christ down from Heaven over and over again to be placed on the altar as the victim thousands of times as Rome claims.
Just as the Old Testament had bloody sacrifices of animals as an offering to God, Jesus gave us the New Covenant and the Eucharist and the unbloody sacrifice of the Mass that we offer to God everyday in most countries.
It is from the teachings of Jesus and from the traditions that were established by Jesus and the Apostles before the New Testament was written.
Do you remember the two travelers to Damascus that welcomed Jesus to their home and finally recognized Jesus in the breaking of the bread?
Sorry that you don’t believe that Jesus Christ is present - Body, Blood and Divinity - at Mass in the consecration of the Bread and Wine. I do hope that the Holy Spirit will eventually enlighten you as was done for St Paul in his trip to Damascus.
There is a good movie out about Paul the Apostle.