"Perhaps you have Chapter 6 in mind, which is, some have thought it was Isaiah's conversion. Some have thought it's Isaiah's calling, but he came face to face with his own unholiness after being exposed to the flying creatures with six wings. The seraphs crying out, 'Holy, holy, holy is the Lord.' The closer he got to the holiness of God, the more he saw his own sin. Boy, that's the way it is.
So he realized that, 'There's nothing clean in me, for I'm a man of unclean lips. I live among a people of unclean lips, but my eyes have seen the King, the Lord Almighty.' The effect of seeing the holiness of God is to see how far we are from the holiness of God, which in itself makes the gospel shine even more because Christ, God has given us His holiness, His righteousness in Christ. Unthinkable. Unthinkable.
I couldn't possibly attain it myself. When I'm close to that light, the brilliance of His holiness, all I see is the stain, but yet, early on in the chapter, early in the book God says, 'Come, let us reason together. Though your stains are sins are deep stains, I will cleanse them.
I will cleanse them though they're double deep, double stained sins, I'll cleanse them out.' Again, you get an echo all through God calling people to repentance, promising that He's going to do the work of repentance, do the work of cleansing so there are gospel themes and gospel echos all through just about every episode that you come across in Isaiah that if you know the whole story they're not hard to see."