Good question. This is how it was explained to me before I was confirmed.
Okay. I believe in my ancestors and deceased family members are all spirits as we will become. So my friend, who known me for years says this:
Think of when your grandmother was a live (physically, mind you). Both of you loved to eat cornbread. That was both of your favorite dish (among many). That's what connected you two together was the food you ate. (I also know that food is very important in many cultures; it can sometimes tell the personality of an individual by what they eat and how they cook). So, my grandmother passes and my friend says "your grandmother's spirit is in the food you both ate." So every time I eat cornbread, I am "eating my grandmother" (Cringes) I am taking in her spirit in me as I know she is still alive and its reconnecting me with her by the food we shared with each other.
It's the same thing as Holy Communion. Except, it is the Spirit of Christ that is within the consecrated bread/wine; it has more of a powerful ring tone.
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Other than that, I try to say it cannot be cannibalism because we (hopefully???) do not see Jesus' toes, fingers, hair, and skin when we take the Eucharist. We
see the hosts; and, we
know it's Jesus.
I can't think of another way to explain it. Good to think about without having to debate it all the time.
Some religion skeptics says its hard to understand christianity as a loving religion when catholics got a understanding of their practise as literally eating and drinking Jesus flesh and blood. Some skeptics have taken it so far to call it for a religion thats strongly influenced by paeanistic traditions, and are not that more civilized than other traditions. They mean that this sacrament have many likenesses to cannibalism.
Do someone have thoughts about this? How can we explain the catholic communion in a good manner in meeting with arguments like this?