Passover Seder

I have heard Christian missionaries claim that although Jews don't realize it, at the seder we single out the middle matza because it represents the Messiah (the three matzot together representing the Trinity), we break the middle matza because it signifies his death by crucifixion, and we then hide the part of the middle matza (called the afikoman) to signify his burial. Finally we "resurrect" the middle matza, just as Jesus is said to have rose from the grave. What is the truth of this claim?

Was the Last Supper a Seder?