God did not direct his call to Isaiah..........Isaiah overheard God saying,... who will go for Us?" The call of God id not just just for a select few but for everyone.
Whether we hear God's call or not depends on the condition of our ears, and exactly what we hear depends upon our spiritual attitude. Many are called but few are chosen ( Matt. 22:14). Few prove that they are the chosen ones. The chosen ones are those who have come into a relationship with God through Jesus and have had led their spiritual condition changed and their ears opened. Then they hear."the Voice of the Lord" asking" .who will go for Us? God does not single us out and say now , Now, you go.
He did not force His will on Isaiah as he was in the presence of God. He overheard His call.
Remove the thought from your mind of expecting God to come to force you or to plead with you. When our Lord called His disciples , He did it without pressure from the outside. The quiet "Follow Me" was spoken to men who sense was receptive.
If we will allow the Holy Spirit to bring us face to face with God, we too will hear what Isaiah heard ----the voice of the Lord.
In perfect freedom we too will say, ""Here am I ! Send me. Isaiah 6:8
GBU
Real ..........