Christ's Apostles were commanded to do so by the Lord Himself. The Greek words usually translated
"Do this in remembrance of Me" can also be rendered
"Offer this as My Memorial Offering". St. Paul says as often as Holy Communion is celebrated, the Church proclaims the Lord's Death until He comes. That means we are commanded to offer the Memorial Offering of the Lord's Body and Blood till He returns.
"The
Eucharist is a true sacrifice, not just a commemorative meal, as “Bible Christians” insist. The first Christians knew that it was a sacrifice and proclaimed this in their writings. They recognized the sacrificial character of Jesus’ instruction, “Do this in remembrance of me” (
Touto poieite tan eman anamnasin; Luke 22:19, 1 Cor. 11:24–25), which is better translated, “Offer this as my memorial offering.”
Thus,
Protestant early Church historian J. N. D. Kelly writes that in the early Church “the Eucharist was regarded as the distinctively Christian sacrifice. . . .
Malachi’s prediction (1:10–11) that the Lord would reject Jewish sacrifices and instead would have ‘a pure offering’ made to him by the Gentiles in every place was seized upon by Christians as a prophecy of the Eucharist. The Didache indeed actually applies the term
thusia, or sacrifice, to the Eucharist.
“It was natural for early Christians to think of the Eucharist as a sacrifice.
The fulfillment of prophecy demanded a solemn Christian offering, and the rite itself was wrapped in the sacrificial atmosphere with which our Lord invested the Last Supper. The words of institution, ‘Do this’ (touto poieite), must have been charged with sacrificial overtones for second-century ears; Justin at any rate understood them to mean, ‘Offer this.’ . . .
The bread and wine, moreover, are offered ‘for a memorial (eis anamnasin) of the passion,’ a phrase which in view of his identification of them with the Lord’s body and blood implies much more than an act of purely spiritual recollection” (J. N. D. Kelly,
Early Christian Doctrines [Full Reference], 196–7)."
Taken from:
https://www.catholic.com/tract/the-sacrifice-of-the-mass
God Bless.