What these words are most commonly used for and what they mean are two very different things.
More accurate definitions:
Holy – like the Lord in nature, different from the world
Communion – fellowship, participation, sharing together
We understand the word ‘community’ and even ‘commune’, but then reduce communion to the taking off a symbolic emblem.
God is bringing us into a fellowship of the saints through the fellowship of His Spirit, which is holy.
When we are born of His Spirit, there is no other outcome but to be in fellowship with those parts in His body. He has placed each of us, very specifically, in His body (in the exact configuration) so as to participate fully in this communion.
God’s purpose was that the body should not be divided but rather that all of it’s parts should feel the same concern for each other.
– 1 Cor 12:25