I’m wondering, what makes Jesus actually be present in the Eucharist?
Like if we put the Eucharist under a microscope there would not be any DNA, it would still be bread.
Yes, but ‘DNA’ is the person. It doesn’t define what or who a person IS.
It’s known as as an ‘accidental’ property. Accidental properties are things that a object (including a person) have, but are not intrinsic and distinctive to them.
My hair color is brown, and my eyes are blue. If I changed those ( or even removed them), I would still be ‘ME’ . If I grew, or got shorter, I would still be ME. Physical appearance does not define the IS.
My DNA isn’t distinctive to me, a hair follicle might have ‘my’ DNA but it is not ‘ME’. Likewise with twins.
Even down to the atomic level. If there was a Star Trek style transporter that replaced every single one of my atoms with another one. I would still be ‘ME’
So we have to look deeper that the physical. The physical can change, even down tot he atomic level. That level we define as ‘substance’ ( which is distinct from who physicists use the term)
The ‘substance’ of the bread and wine change. It changes ‘what it IS’, but the accidental properties ( what it looks like, smells, like, weighs, and yes even the molecular\atomic level) remain the same.
Does that help?