BK video 4-22
We will have gained much from the sacrament if this knowledge is engraved and etched on our hearts: we cannot harm a brother, slander, mock, scorn or in any way offend him, without harming, slandering, mocking, scorning or offending Jesus Christ in him. We cannot disagree and fall out with our brothers without disagreeing and falling out with Jesus Christ. We cannot love Jesus Christ without loving him in our brothers. The care and concern which we have for our own body, we must also have for our brothers who are members of our body. Just as no part of our body can experience pain without every other part feeling the same, so we must not allow our brother to suffer any affliction in which we do not also share out of compassion. It was thus with good reason that Augustine so often called this sacrament ‘a bond of love’. For what goad could be sharper and keener in encouraging us to have mutual love among ourselves than when Christ, in giving himself to us, not only invites us by His example to give ourselves and to risk our lives for each other, but in making Himself one with us makes us all truly in Him.
- excerpt from Calvin's Institutes of the Christian Religion