Referencing an article by David Ganz, Reformed theologian Peter J. Leithart points out that in the early middle ages, at the Council or Synod of Macon in 585, a decree was made, with these words:
We have learned from the report of the brethren that some churches in some places have deviated from the divine command in not offering a host at the altar. Wherefore we decree that on every Sunday an offering of both bread and wine be made to the altar by all men and women, that by these oblations they may obtain the remission of their sins.
One interesting note to make here, is that this is not written in what is commonly referred to as ‘the dark middle ages.’ This is a very early period of the medieval times, during the period often referred to by talking of ‘the undivided Church’ or ‘the undivided Church of the first millenium.’
What we see here is the Offertory, that the Church, by her members and through the priest, is offering up bread and wine to God, representing themselves. It can be seen as an expression of what Paul, in Romans 12:1, calls a ‘reasonable service,’ the offering up of our bodies, ourselves, as “a living sacrifice, holy and acceptable to God,” and of what Peter, in 1. Peter 2:5, calls us to when he urges us to be “built into a spiritual house, to be a holy priesthood, to offer spiritual sacrifices acceptable to God through Jesus Christ.” Leithart makes the point that “it is the gathering up of the communal oblation in the Mass that has [the effects described], but the point is that the people participate in offering the host by providing the materials for the immolation of the Mass.” We can see this expressed by Paul elsewhere. In Romans 15:16, Paul points out that he has received a grace from God “to be a minister of Christ Jesus to the Gentiles, serving as a priest with the Gospel of God, so that the offering of the Gentiles might be acceptable, sanctified in the Holy Spirit.” (My translation)
Note that Paul, through his ministry, is offering up the offerings of the Church. The use of the Genitive here (“the offering of the Gentiles”) can be seen both as subjective (the offerings that the Gentiles are offering up) and objective (that the Gentiles themselves are being offered up). It is a self-offering. We see this also elsewhere, where Paul, writing to the Philippians (Phil 2:17), reference his service and “the sacrificial offering of your faith” or “the sacrifice and service of your faith” (my translation).
But the main point I want to point out is that the offerings written of in the Council or Synod of Macon in 585, and mentioned by Leithart, were not only offered up as thanks and praise, but with the express purpose that “by these oblations [the people] may obtain the remission of their sins.” The question now becomes: What does this text say: Does it say that the offering, the giving up of these gifts grant forgiveness, or does it say that through these offerings, which will be consecrated and will become the body and blood of Christ, the Church will receive forgiveness?
It seems to me that the latter is the ‘correct’ approach. The decree, it seems, doesn’t say that these offerings merits forgiveness, in and of themselves, but that the sacrifice of Christ is made present in these offerings through the Eucharistic celebration, and that these offerings are then given back to the Church, and that the Church receives forgiveness though partaking of these consecrated gifts. This perspective is also found in the Roman Canon, the way this is expressed in the first Eucharistic prayer of the Ordinary Form of the liturgy of the Catholic Church. We read there, in the prayer just after the Sanctus (holy, holy, holy), and before the consecration:
To you, therefore, most merciful Father, we make humble prayer and petition through Jesus Christ, your Son, our Lord: that you accept and bless these gifts, these offerings, these holy and unblemished sacrifices, which we offer you firstly for your holy Catholic Church. Be pleased to grant her peace, to guard, unite and govern her throughout the whole world, together with your servant N. our Pope and N. our Bishop, and all those who, holding to the truth, hand on the catholic and apostolic faith.
Remember, Lord, your servants N. and N. and all gathered here, whose faith and devotion are known to you. For them, we offer you this sacrifice of praise or they offer it for themselves and all who are dear to them, for the redemption of their souls, in hope of health and well-being, and paying homage to you, the eternal God, living and true.
In communion with those whose memory we venerate, especially the glorious ever-Virgin Mary, Mother of our God and Lord, Jesus Christ, and blessed Joseph, her Spouse, your blessed Apostles and Martyrs, Peter and Paul, Andrew, (…) and all your Saints: we ask that through their merits and prayers, in all things we may be defended by your protecting help. (Through Christ our Lord. Amen.)
Therefore, Lord, we pray: graciously accept this oblation of our service, that of your whole family; order our days in your peace, and command that we be delivered from eternal damnation and counted among the flock of those you have chosen. (Through Christ our Lord. Amen.)
Be pleased, O God, we pray, to bless, acknowledge, and approve this offering in every respect; make it spiritual and acceptable, so that it may become for us the Body and Blood of your most beloved Son, our Lord Jesus Christ.
The Roman Canon is filled with sacrificial language, and the priest offering the prayer asks that God accept the offerings — of prayers, of thanks, of praise, of bread and wine — “for the redemption of their souls.” This recalls the words of the Council or Synod of Macon in 585, stating that the Christians should each Sunday offer bread and wine on the altar, “that by these oblations they may obtain the remission of their sins.” It is understandable if this is weird, but if we read this in light of teaching as a whole, it is my understanding that neither this decree nor the Roman Canon say that we merit our own salvation, but that when we offer our gifts to God, in praise and thanksgiving, they are transformed. And through this transformation they “become for us the Body and Blood of your most beloved Son, our Lord Jesus Christ,” to use the words of the Roman Canon.
Both in Lutheran and Catholic theology we emphasize that in the celebration of the Lord’s Supper, the Eucharist, the elements of the sacrament, bread and wine, our gifts, the fruits of the earth, of the wine, and of human labour, are consecrated, sanctified, and that Christ becomes present in the sacrament through this consecration. Contemplating this, and contemplating the fact that the word ‘Eucharist’ means ‘thanksgiving,’ consider the following words by St. Paul, translated by your truly: “For every creature of God is good, and nothing is to be rejected if it is received with thanksgiving; for it is consecrated through the word of God and prayer.” (1. Timothy 4:4-5)
 David Ganz, “Giving to God in the Mass: the experience of the Offertory” (The Languages of Gift in the Early Middle Ages, ed. Wendy Davies & Paul Fouracre. Cambridge University Press 2010), p.21 (18-32).
 Peter J. Leithart, “Offering the host” (Peter Leithart’s Blog, Dec. 12, 2012). Retrieved Dec. 19, 2012.
 If not otherwise noted, all Scripture quotations are from the Revised Standard Version, RSV.
 See Thomas E. Woods Jr., “Extraordinary Form 101: A Beginner’s Guide to the Old Latin Mass.” This Rock Magazine 19:9, pp.6-11. For a popularized introduction to the Roman Canon, in its present day ‘ordinary’ form, see Milton Walsh, In Memory of Me: A Meditation on the Roman Canon (San Francisco, CA: Ignatius Press 2011). I use the translation from this book when I quote the Roman Canon.
 Just as a reminder for Lutherans: Luther, in the Smalcald Articles (part I:VI), held that Christ “was born of the pure, holy [and always] Virgin Mary.” He therefore held that Mary was ever-virgin.