I was thinking about the calls of Isaiah and Peter as we have them in the readings for Mass today.
It's funny; we tend to think of heaven as pleasant, or at least comforting--at funerals we are consoled by our hope that the faithful departed are now on their final journey to heaven and we take courage for our own lives in looking forward to heaven ourselves--but the prophet Isaiah, faced with the heavenly court, is afraid. Finding himself in that blessed firmament, the first thing created after the light, Isaiah can only say, "Woe is me! For I am lost." (Isaiah 6:5a, RSV)
The case of Peter in the gospel today isn't so different. Having accepted Jesus' invitation and having witnessed the fruit of his obedience in the miraculous catch of fish, Peter's reaction is to try to distance himself from Jesus: "Depart from me, Lord, for I am a sinful man." (Luke 5:8b, NAB)
The work of grace in our lives can make our sinfulness all the more obvious, certainly to ourselves and often to others as well. The more we consent to God in trusting him--as Peter did by going back out into deep water, already tired, and casting the nets--the more obvious our unworthiness becomes. The invitation in this is to see how good God is to all, but there is always the temptation to push God away in the inverted pride that doesn't want to accept the vulnerability of being so loved precisely as one who is unworthy.
How does God respond to these expressions of lostness and distance expressed by Isaiah and Peter? With Peter, Jesus doesn't even remark on the confession of sinfulness. He doesn't say, 'Your sins are forgiven.' Nor does he do the 'nice' thing and say, 'Oh, you're not so bad.' All Jesus says is 'Do not be afraid' and then gives Peter his mission as a catcher of men. Peter is called as one who confesses that he is a sinner, a sinner who is commanded not to be afraid. He is a sinner who, for the glory of God, will now bear into the safety of the Church a miraculous catch of other sinners.
And it is there, caught by Jesus through Peter into the Church, that we have the experience of Isaiah. As Isaiah is feeling lost and doomed before the majesty of God, one of the seraphim takes a burning coal from the altar and touches it to his mouth. With this, his sin is forgiven and he is empowered to announce his willingness to be sent as a prophet.
Here we can see an image of Holy Communion.
"There is no way but through the burning love of the Crucified," says St. Bonaventure. The blessed Host is that burning coal taken from the altar, burning with the love that is Christ crucified, and willing in sublime humility to touch our mouths and thus be received into our bodies, souls, and lives. It is the fire that burns away our guilt and shame and frees us to burn only for God and the salvation he is just dying--literally--to give to the world.