In Isaiah’s vision of God, the prophet is transported to the Holy presence of the living God! Even as he sees his own frailty and unworthiness and the brokenness of his culture (unclean lips), grace is immediately extended to cleanse him. Now, Isaiah also is part of the heavenly conversation, not as an angel, but as one who can go in service for the Lord among the people.
In John 3, Jesus has a conversation with Nicodemus about the kingdom of God. Human beings cannot participate in this “God reality” without first being given a new life from God’s Spirit. Jesus is surprised that a faithful Jewish leader like Nicodemus, who can see that God’s presence is with Jesus, cannot understand that it is the Spirit of God who comes to give this new kingdom life.
In Romans 8 Paul contrasts the flesh and the Spirit, much as did John chapter 3 above. There is “flesh” – human life lived by its own resources; and there is another kind of life lived by the Spirit which adopts us and leads us. Jesus, who was lifted up first on a cross and then ascended to the presence of God, gives this Spirit life to those who believe/trust/hope in him.
Comment: Why were these readings selected for Trinity Sunday? Perhaps because they show the work of the Holy God, who restores human beings with God’s own Spirit and purpose through the Son who is lifted up on the Cross. Let us praise the God who reaches to our unclean and hurting lives with his healing fire, includes us in his conversation, and asks if we are willing to be people sent into our world by God’s own Spirit.