The Eucharist is such a common part of Christian worship that it's easy to overlook how strange it is — drinking wine that represents Jesus's blood, eating bread that represents His flesh. The ritual would have been even more shocking to Jesus's Jewish followers, for whom consuming blood (even metaphorically) was absolutely forbidden. The New Testament says that Jesus himself instituted the Eucharist at the Last Supper, but earlier writers like Paul describe something more like a communal mea...