Tom: We have no record in the Gospels, as to whether the disciples believed that it was His body and blood or that it was merely bread and wine, and that they may have believed Jesus was speaking metaphorically as when He called himself a vine.
Bread From Heaven: Jesus was not speaking metaphorically as in when He says I am the vine, or I am the door. I have addressed this common Protestant work-around for the literal interpretation of John 6 in the following posts.
Tom: It may well be that the disciples did “not discern the Body and Blood of Jesus”.
Bread From Heaven: I see how you might think even the disciples did “not discern the Body and Blood of Jesus”. We don’t know b/c we have not been left a record. But, even if they did not discern or were totally confused at the Last Supper, this was all VERY new and our gracious Lord would give them grace during this time of transition. Surely, after the resurrection they understood, a short three or four days later.
But, I think it is very likely that the Last Supper was a big “Ah Ha!” moment for them. A year earlier at near the time of the Passover, Jesus had multiplied the bread and fish and then told everyone that they must eat His flesh and drink His blood in order to have eternal life. Many others left Jesus but the disciples stayed but were surely puzzled by this seeming reference to what sounded like cannibalism.
So, when Jesus said of the bread, “Take and eat; this is my body.” and of the cup “Drink from it, all of you. This is my blood of the covenant, which is poured out for many for the forgiveness of sins.” They must have breathed a sigh of relief and thought, Oh! So, this is what Jesus meant last year about eating His flesh and drinking His blood.”