I would like to take two different people from the Bible, one from the Old Testament and the other from the New Testament and compare them as they both experience seeing God. They both had a similar, life changing experience.
In Isaiah 6, we see Isaiah as he encounters the true and living God. For some reason, he never saw this until this point in his life. First, he has a vivid description of God. He now 'sees' God with eyes he never had before. He sees God in His holiness now. Compare that with the man in the New Testament named Peter. Peter was learning who Jesus was, but suddenly one day, his eyes were opened to something he had not ever seen.
After Isaiah saw God, his words were "Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for my eyes have seen the King, the LORD of hosts." (Isaiah 6:5). Here is what Peter said in Luke 5; "When Simon Peter saw it, he fell down at Jesus' knees, saying, Depart from me; for I am a sinful man, O Lord.". What was it that both Peter and Isaiah saw? They saw the holiness of God. They both also saw their sin.
Both responses were almost identical. Both Isaiah and Peter immediately saw their sin. They both knew their sin had to be dealt with. In Isaiah, the angel brought hot coals to Isaiah's lips. Jesus told Peter to not be afraid, for he would now be catching men.
Peter's story goes back to a time when the men were fishing all night. Fishing was Peter's occupation and he depended upon catching fish for his livelihood. Peter was down on his luck, so to speak, and he and his companions did not catch any fish during the night. What a waste of a night! Or was it? What was God going to do to turn this unfortunate night around, and use it for His glory?
He was going to use Peter's challenging situation to show forth His power in holiness. That is exactly what happened. Peter saw God's holiness when Jesus did what only God can do in a situation like that. And he realized at that moment that he was on holy ground.
What did those incidences produce in Peter and Isaiah? It produced repentance and faith. They both recognized their sin and God's holiness, and that something needed to be done to fix the problem.
Once all of the sin was dealt with, they were both commissioned to preach the Gospel. In Isaiah, God asks the question 'Who shall I send, and who will go for us?'. Isaiah answered, 'Here I am. Send me". (I like verse 8. It has a hint of the Trinity in it). But with Peter, Jesus told him that he would be catching men from that point on.
The important thing is that they saw their sin and didn't want it anymore. God dealt with it, then commissioned them to tell the Gospel. This is what should happen in our evangelism. The Bible says that 'Salvation is of the Lord'. God reveals Himself to people, and when that happens, they have new eyes to see Him. Salvation is no longer a formula to follow in order to escape hell. The issue has been dealt with. The people who see God understand that He is so holy, and they are so sinful, and they need help.
Notice also, that neither Peter nor Isaiah 'cleaned up their act' before God. They made the mess in the first place, but God cleaned them up as they acknowledged their sin and their need for help.
Let us pray for those we talk to, that they will have eyes to see the Lord, and that God will be gracious to them and grant them repentance and faith. Pray that God would open up their hearts and minds to the Scriptures as we communicate the Gospel to them, and may God soften their hearts to the Gospel message.