The Church that Luther believed was the Church of the real presence. … Perhaps there are many among us who have…taken offence that Luther remained so stubborn in the strife over the Lord’s Supper concerning the meaning of the words of institution: ‘This is my body.’ That is not his obstinate nature but his great worry that the Church of the Reformation would lose that upon which the Church has always lived, … If Christ is in a heavenly location far from this world, where he has only left behind authority, orders, and commands; if we confuse him with our fantasy, and must visualize him with our faith; if he is only present according to his divine nature, and not also according to his human nature as the God-man, who has taken on our poor flesh and blood, and is present with us according to his humanity, as he is present with the Father according to his divinity, then we are a lost little band in this world. Because, we have to admit that without him we are nothing, that without him and his presence, the Church is a helpless, poor, despairing band of men.

from Witness (2013), 318. Originally preached 1943.

See also Luther on the present Christ.