Joseph Ratzinger reflects on Romans 12:1-2 in his Theology of the Liturgy (349-51), which is evident in the Roman Canon's prayer that “our sacrifice may be rationabilis.” He writes:
It is not enough—indeed, it is quite wrong—to translate this as saying that it should become rational. We are asking rather that it may become a logos-sacrifice. In this sense we are asking for the gifts to be transformed—and then, again, not just for that; rather, this petition is going in the same direction as suggested by the Letter to the Romans: We ask that the Logos, Christ, who is the true sacrifice, may himself draw us into his act of sacrifice, may ‘logify' us, make us ‘more consistent with the word,' ‘more truly rational,' so that his sacrifice may become ours and may be accepted by God as ours, may be able to be accounted as ours. We pray that his presence might pick us up, so that we become ‘one body and one spirit' with him. We ask that his sacrifice might become present not just in an exterior sense, standing over against us and appearing, so to speak, like a material sacrifice, that we might then gaze upon and regard as men once did the physical sacrifices of old. We would not in that case have entered into the New Covenant at all. We are asking rather that we ourselves might become a Eucharist with Christ and, thus, become acceptable and pleasing to God.
This is not a moralizing, a-liturgical portrait of the Christian life. Rather, “the Logos, who is the Son, makes us sons in the sacramental fellowship in which we are living. And if we become sacrifices, if we ourselves become conformed to the Logos, then this is not a process confined to the spirit, which leaves the body behind as something distanced from God.” As we participate in the Eucharist we are “drawn into the fellowship of love with God in our entire bodily existence, in bodily fellowship with Christ.”
Reflecting on Paul's use of priestly terminology to describe his apostolic ministry (Romans 15:16): “The Eucharist, if it continued to exist over against us, would be relegated to the status of a thing, and the true Christian plane of existence would not be attained at all. Conversely, a Christian life that did not involve being drawn into the Pascha of the Lord, that was not itself becoming a Eucharist, would remain locked in the moralism of our activity and would thus again fail to live up to the new liturgy that has been founded by the Cross. Thus, the missionary work of the Apostle does not exist alongside the liturgy; rather, both constitute a living whole with several dimensions” (353).