In Sunday school this week the teacher was discussing the story of Isaiah's commission in Isaiah chapter 6. In a nutshell, Isaiah had a vision of the Lord in all His glory, and Isaiah immediately assumed that because of his impurity, he was going to die. An angel brought a glowing coal from the altar fire, so hot that even the angel had to hold in in tongs, and touched Isaiah's lips and purified them. God then spoke a question: "Whom shall I send, and who will go for us?" Isaiah immediately answered, "Here am I! Send me."
The thing that struck me was how quickly Isaiah went from "Woe is me! For I am lost..." to "Here am I! Send me." From fear to boldness in one single step... the purifying power of God. What is it that purifies? What is it that the sacrifice on the altar represented? The sacrifice of Jesus, the shedding of His blood. When the power of God touches us, it immediately inspires us to service!
(By the way... I can never read that story without thinking of this song...)