In response to a critique of Thomas Aquinas’s views on the law from Michael Wyschogrod, Matthew Levering argues (Christ’s Fulfillment of Torah and Temple) that “the Mosaic law . . . is still observed by Christians” (his emphasis).
Exactly right. And it gets better when Levering elaborates, “Christ’s passion not only fulfills but also perfects and elevates the Mosaic Law: Christ fulfills and transforms the moral precepts through his most perfect (supernatural) love of God and, in God, of all human beings; his perfectly free and loving self-sacrifice on the cross fulfills and transforms the animal sacrifices and purity laws; and his suffering and death . . . fulfill and transform the judicial precepts by paying an interior ‘penalty’ that is sufficient to rectify, from the inside, all the disorder caused by sin in human history” (28).
For Thomas, though, the fulfillment doesn’t stop with the passion of Jesus. By the New Law (that is, by the grace of the Spirit) believers participate in the passion of Christ and thus the law is fulfilled also in us: “the Mosaic Law has been fulfilled by Christ, so people observe it by conformity to Christ in the community of the Church. . . . Christians, by sharing in Christ’s passion, will forever observe the ceremonial and judicial precepts—although now in the way proper to a universal ‘body’ that enjoys trinitarian communion through Christ the ‘Head’” (29).
To this, we can add that Thomas doesn’t think of “sacrifice” in some generic way, as an act of sacred violence or some such. He specifies various sorts of sacrifice in the Old Law—holocausts, peace offerings, and sin offerings—and argues that each is fulfilled in Christ’s passion in a particular way (55). Christ fulfills the burnt offering by offering His whole self; the peace offering by offering in thanksgiving; and the sin offering insofar as He offers (in Thomas’s words) “on account of man’s need for the forgiveness of sin.” Though Levering doesn’t explicitly make the point, we might say that Christ’s variegated fulfillment of the Old Testament sacrificial system is also fulfilled in the Church, as believers offer themselves wholly to God, as they offer in thanksgiving and joy, as they bear one another’s burdens and pray for erring brothers.
And to that, the only thing to add is: Three cheers for Thomas!