5 Then the Priest says, “Let us give thanks unto the Lord.” For verily we are bound to give thanks, that He called us, unworthy as we were, to so great grace; that He reconciled us when we were His foes; that He vouchsafed to us the Spirit of adoption. Then ye say, “It is meet and right:” for in giving thanks we do a meet thing and a right; but He did not right, but more than right, in doing us good, and counting us meet for such great benefits.
Source: Catechetical Lectures (New Advent)