Click here for the reading: Isaiah 6:1-7.

The threefold “Holy” of the seraph in the throne-room of God is our connection to theme of Trinity Sunday. Who is this God that has called a people to be his own? Who is the King above all kings, in whose hands are the deep places of the earth? He is not impersonal, nor is he like the gods of the nations – capricious and capable of wickedness. His holiness is manifest in the unity of three persons in a perfect bond of love.

The grandeur of the sight is such that Isaiah can only describe the smallest detail of it: the train of Lord’s robe filled the temple. Isaiah saw the Lord of hosts, which means that he saw Father, Son, and Holy Ghost, a majesty and glory that leave him undone. The angels are not undone by the presence of God; nevertheless, even they cover their faces and their feet. What hope does a man have, much less a man of unclean lips, in the presence of Almighty God?

In the year that King Uzziah died, this commissioning of a prophet in the presence of God’s throne is poignant given the circumstances of Uzziah’s death (2 Chron. 26). No king of Judah, even though he seeks the Lord, can keep himself clean. Much less can he cleanse the people. The Lord must provide the cleansing himself. That cleansing does not happen merely by means of fire, which would burn but not save. Nor, as our Gospel lesson will reveal, does it happen merely by means of water, which would drown but not save. Rather, the cleansing needed comes by means of a word, which is why a prophet is commissioned in the throne room of God.

The blessings of God are not generic blessings. For Isaiah, who is to serve as God’s mouthpiece to Israel, it is precisely his lips which need cleansing. The burning one purifies his mouth with fire and a word of forgiveness. Now Isaiah can stand without terror in God’s presence, and he can speak with authority to an unclean people. What can lips thus cleansed do besides proclaim the holy and pure Word of God?

What follows in Isaiah is 60 chapters of prophecy that burn hotter than any fire could. It is a word that removes every excuse and warns against all deceit. It does not satisfy itching ears. It shatters the people and is a snare to the proud. But having razed the dull with their heavy ears and their blind eyes, God’s Word sprouts anew in the virgin who shall conceive. The Holy Trinity, in its majesty eternal, stoops to save sinners as the Son of God takes on human flesh and suffers as an obedient servant, as a lamb led to slaughter. That Spirit-breathed Word, the Gospel of forgiveness and salvation for man, reveals the glory of Father, Son, and Spirit, whom we worship and adore.