Christians have never believed in the Eucharist...
You know you’re talking to a willingly blank wall when you see someone who thinks that the Christian martyrs, even those who wrote eloquently on the Real Presence in the Holy Eucharist, went willingly to their death for these beliefs but never believed in the Eucharist.
Might as well put your effort into convincing an ostrich that the sky is blue. Or just forego giving any credence to such a silly argument altogether.
You aren’t a Christian.