As we said yesterday, the Lord’s Supper presents us a picture of our salvation past, present and future.
So in what sense are we saved in the present tense, and what does Communion have to do with it? Here’s a simple summary of it. We were saved from the penalty of sin, which was justification. We are saved every day from the power of sin, which is sanctification. And we will one day be saved from the presence of sin, which will be glorification. Today, day by day, moment by moment, our Master offers us freedom from the power of sin.
How do we acquire this, and what does it have to do with us "[eating his] flesh and [drinking his] blood”? Of course, the Roman Catholic Church loves this passage, since they claim it teaches transubstantiation, the belief that when the elements are blessed, they literally become the body and blood of the Lord. The interesting thing about this is that the Jews who had been following him up to this point interpreted this literally as well, and most of them abandoned him because of it. But in the context of the chapter, Jesus makes it clear that the way we “eat and drink” him is by believing in him, not through any physical action like taking Communion, which didn’t even exist as an ordinance when the Lord was speaking these words.
So if we “eat and drink” him by believing in him at the beginning, does this have anything to do with our life with him after we’ve received him? Of course it does: That’s why he mentions that those who eat his flesh and drink his blood “remain” in him, and he in us (vs. 56). This is the whole idea of the present aspect of salvation in the Lord’s Supper—he doesn’t just save us, pat us on the back and say “Good luck with that!” He sustains us day by day, moment by moment. He “feeds” us and sustains us. His life becomes ours.
Per usual, C.S. Lewis has a wonderful way of illustrating this point. In his poem (you didn't know he wrote poetry, did you?) "On A Theme From Nicolas Cusa," he writes
When soul and body feed, one sees
Their different physiologies.
Firmness of apple, fluted shape
Of celery, or tight-skinned grape
I grind and mangle when I eat,
Then in dark, salt, internal heat,
Annihilate their natures by
The very act that makes them I.
But when the soul partakes of good
Or truth, which are her savoury food,
By some far subtler chemistry
It is not they that change, but she,
Who feels them enter with the state
Of conquerors her opened gate,
Or, mirror-like, digests their ray
By turning luminous as they.
So have you “fed” upon him today? Are you feeding upon his word, basking in his Presence, listening to his voice? What makes you think you can make it without that?
And as a special treat, here's Rich Mullins's "Peace (A Communion Blessing From St. Joseph's Square)":
Lord Jesus, you sustain me with your life, and you’re in the process of changing me into your likeness. Any way I can cooperate with that, please show me and give me the strength to do it.