Covenant? O.K. but what Kind?

Matthew 26:26-29 (ESV)
Now as they were eating, Jesus took bread, and after blessing it broke it and gave it to the disciples, and said, "Take, eat; this is my body." [27] And he took a cup, and when he had given thanks he gave it to them, saying, "Drink of it, all of you, [28] for this is my blood of the covenant, which is poured out for many for the forgiveness of sins. [29] I tell you I will not drink again of this fruit of the vine until that day when I drink it new with you in my Father's kingdom."

Take Eat; this is my body. Drink of it all of you, for this is my blood of the Diatheke, which is poured out for many for the forgiveness of sins. I talked with an exegete the other day, he maintains that Diatheke is better translated covenant than Testament, and so uses the word covenant in the word’s of institution. No one has ever rioted over that he informs me. How far we have come, or fallen. In Augustines day a riot broke out when the word vine was switched out for Ivy in the story of Jonah.
It was an interesting conversation though. I abject to the use of the word covenant. Not that the Lord’s Supper isn’t a covenant, or that diatheke can’t be translated that way, though in secular Greek it was more often used for Testament, which is a special type of “covenant.” He argued from the Septuagint that “where the word covenant occurred in the Hebrew it was translated Diatheke in the Greek. I always thought that was just great commentary in translation as to the true meaning of covenant in the Old Testament.
I told this exegete, whom I have grown to admire and respect, and yet still disagree with him here, that I don’t like the word covenant, because it carries the connotation of a two way street, a compact, a contract between two people each doing their own part, where testament is a special kind of covenant in which one party does the doing, and the other just receives the benefits. A testament is a will. And that is what the Lord’s Supper is. To which he says, yeah the word covenant is never used as a mere contract in the Old Testament, but is always from God to his people, a one way street. So we go round and round. We can use covenant as long as by covenant we mean Testament. Alright. Or perhaps we can forgo the riots, and use the word Testament as it has been in our liturgy from the beginning.
Simple words though really. This is my Body, This is my Blood. They mean what they say. People want to make it represent something. I don’t know how that is at all helpful. I do know how it is disastrous though. Calvin and Zwingli both had a problem with the miraculous nature of this. I always think they are the reason people distrust miracles so much in our day, they taught the church to distrust the miracle. How can bread be the body of Christ? Because Christ, God, says it is. And that is just it, this representation stuff is at it’s core a denial of the divinity of Christ that cannot be maintained in light of the resurrection. Well now that is gone too in many sectors of what used to be Christendom. If Jesus can’t make bread be his body, and wine his blood, then he probably can’t walk on water either. I’m just not into telling God what he can and can’t do. But here we partake of the sacrifice Jesus made for us on the Cross, the true Passover, as our Passover Lamb, and the Passover Lamb must be eaten, all of it consumed. That is how you participate in the Passover, you eat the lamb sacrcificed, or the angel of death does not fly over, but visits your house.