God called Isaiah to be a prophet. Isaiah 6:8 says, “Also I heard the voice of the Lord, saying: Whom shall I send, and who will go for Us? Then I said, Here am I! Send me.”

Jesus taught through parables. Mark 4:12 was a quote from Isaiah 6. It says, “So that Seeing they may see and not perceive, and hearing they may hear and not understand…” To His disciples He gave the interpretation. 

We have the Holy Spirit. 1 Corinthians 2:9 was a quote from Isaiah 64:4. It says, “…Eye has not seen, nor ear heard, nor have entered into the heart of man the things which God has prepared for those who love Him.” 

Verse 10 in the Amplified says, “Yet to us God has unveiled and revealed them by and through His Spirit, for the (Holy) Spirit searches diligently, exploring and examining everything, even sounding the profound and bottomless things of God (the divine counsels and things hidden and beyond man’s scrutiny).”