Isaiah's vision of God (Isaiah 6) changed him forever. Immediately, he saw his own sinfulness and need for a merciful Saviour (Isaiah 6:5-7). It also helped him recognize the woeful shortcomings of his own people. As a result, Isaiah became a prophet that warned Israel of coming judgment (Isaiah 1-39). The good King Hezekiah and all of Israel was deserving of such punishment (Isaiah 39:5-7).
This vision gave Isaiah hope. He spoke of a coming Messiah who would take away the sins of the world (Isaiah 40-66). In fact, it would seem that Isaiah longed for such a coming. In Isaiah 64:1 we read, "Oh that you would rend the heavens and come down, that the mountains might quake at your presence."
Eight centuries later, the heavens were "torn open" (Mark 1:10) and God revealed Himself in a most remarkable way. God the Holy Spirit descended upon God the Son as God the Father spoke. Isaiah's prophecy became a reality. God now dwelt with humanity. Jesus embarked on His three year ministry, a ministry that would culminate in His saving death and hope filled resurrection.
As we journey through the Gospel of Mark, may we clearly see Jesus and be moved to radical obedience.