The Lord condescends to our weakness. Were we made up all of spirit, there would be no need of bread and wine. But we are compounded creatures. Therefore God, to help our faith, not only gives us an audible word but a visible sign.
Things taken in by the eye work more upon us than things taken in by the ear. So, when we see Christ broken in the bread and, as it were, crucified before us, this more affects our hearts than the bare preaching of the Word."