The Mass is based on the same understanding that underpins the yearly passover feast, clelebrated both in Jesus’ days, and now.
When jews gather to “remember” the original exodus they are not simply recalling the past as a done event, but actually calling those events into the present so that they become a real & substantial experience that allows all jews at all times to experience the escape from slavery towards nationhood.
When the early Church celebrated the eucharist it was with the same understanding, since, of course, the mass is based on the passover supper. So, we do not simply recall the crucifixion as a past event, a done deal, if you will, but as something which we experience here and now, across time & space, as the eternal & significant sacrifice which has gained us our redemption.
This is why the mass is also a sacrifice, since we are, for all intent & purposes, in the upper room and on Calvery while the events unfold.
so, you can see, even from this short and inadequate explanation, that the catholic belief is firmly based on the thoughts and practices of 1st century judaism, which is what Jesus and the early Church would have understood. Most protestants have moved so far from biblical times that they have lost this understanding, which is ironic when you consider how reliant thay are on the Bible!!!
Hope this helps
