We know what Jesus said, but what exactly did he mean?

Here’s what he said: "I am the living bread that came down from heaven; whoever eats this bread will live forever; and the bread that I will give is my flesh for the life of the world."

Jesus appears to be saying that whoever receives the Eucharist (even once) will definitely go to heaven—as if receiving Holy Communion guarantees a person’s eternal salvation.

Is that what he meant?

Well, to answer that question, we need to think of the natural food we eat every day, because there’s always a parallel between the natural and the spiritual. (God has designed the universe in this way: by means of the natural world he gives us insights into spiritual realities like the Eucharist.)

Consider, now, the natural food we eat at breakfast, lunch and dinner. For that food to nourish us in the way that it’s supposed to, certain conditions must be met. First of all, the quality of the food has got to be good: spoiled food can make you seriously ill. (Some of us, I’m sure, know this from our own experience! We’ve been in the emergency room at some point in the past because we ate something that we shouldn’t have.)

But that’s only half the story. Even if a plate of fresh, well-prepared, gourmet food is set before us at a given meal, it will still not have its proper physical effect in us if our personal health is bad.

This is also easy to illustrate: Most of us have had the very unpleasant experience of getting sick and then losing our desire to eat. All of a sudden, our appetite is gone. The foods we normally love become distasteful to us. And if we try to "force them down," so to speak, our body may actually reject them. (I don’t think I need to go into greater detail on that point. You know exactly what I mean!)

So, on the natural level, if food is to nourish us, it must be good and our physical health must be good.

Well, not surprisingly, a parallel truth applies on the spiritual level. Simply put, if we are to receive spiritual nourishment from something, the spiritual food we are consuming must be good, and the health of our soul must be good.

And this is the key point, which will help us to make sense of what Jesus says in this text concerning the connection between the Eucharist and eternal life.

Now with respect to the Blessed Sacrament, there can be no question about the quality of this spiritual food: it’s the best—the very best—since it’s the Lord’s own Body and Blood.

But if our soul is not in good health—that is to say, if we have committed a mortal sin, and not brought it to Confession yet (a sin like missing Sunday Mass, or an act of sexual impurity)—then the Eucharist will not have the spiritual effect that it’s supposed to have in us! When we’re physically sick, our bodies can’t process good, natural food properly; and when we’re spiritually sick, our souls can’t "process" the Eucharist properly.

This is why St. Paul told the Corinthians to examine themselves before they came to Communion. He wanted them to receive strength, comfort, peace—and eternal life!—from the Body and Blood of the Lord. But he knew that that wouldn’t happen, if the Corinthians were in the state of mortal sin. They would commit a sacrilege instead.

So obviously there’s an implicit condition present in those words of Jesus we heard a few moments ago: "I am the living bread that came down from heaven; whoever eats this bread will live forever; and the bread that I will give is my flesh for the life of the world."

The condition? To be in the state of grace! Eternal life comes by receiving the Eucharist, yes—but only when a person receives it worthily.