This brief passage from Isaiah is an excellent one for showing both the necessity for and the task of evangelism. While it does not have a place in the ecumenical three-year lectionary cycle, it would be appropriate for the Epiphany season with the emphasis on the witness to the world as seen in the Magi. It would also be appropriate in Ordinary Time when the character of our Christian discipleship is a strong emphasis. When a baptism is celebrated, it could form the text for a sermon on the meaning of Baptism.
The setting is Israel in captivity. The reality of Yahweh was probably quite distant. After all, the nation had been defeated and many of its people were dispersed among the nations. Surely, if their God were truly powerful and loving, such a thing would not have happened. Yet this was not the only possible opinion, although obviously it could have been quite popular among the conquerors of Israel. The immediately preceding chapters declare that it was Israel's own sin and unfaithfulness to God that had led to such punishment. Rather than showing God's weakness, their defeat was the result of God's power.
In this sad setting, there comes this call for Israel to return to its task of being God's witness in the midst of the world. They may not be ready for such a call because though they have eyes and ears, they have not really used them recently and therefore appear blind and deaf.
The term "witness" connotes a law court where someone is on trial. There is also a judge and an accused. The roles are clear in this passage: Israel is the witness, called by God who is the judge (as well as the prosecutor), and the accused are the other nations who worship other gods.
What is the task of the witness! In this case, it is to declare the words and actions of God, especially to point to God's promises or threats in the past that have been carried out. By so doing, Israel makes very clear that the God of Israel is real and is powerful. God has done things in the past: The whole tradition of Israel from the exodus to the conquest and the monarchy points to that. God has punished the nation when it was disobedient: The destruction of the Northern Kingdom and the current unhappy situation of the Southern Kingdom bear testimony to that. Israel knows that it is God who has done these things because God spoke through the prophets to make it clear--even before the events took place. Now Israel is to speak and declare to the whole world what it has heard and seen. This is what it means to be God's witness.
Then the other nations are called to give their testimony. Do their gods have such witnesses? Obviously not. They have not said in advance what they were going to do; they have not raised up prophets to give such knowledge to the people. These nations may worship other gods, but these gods do not have witnesses because they have no reality. They are idols. They neither speak nor act. Therefore they cannot have witnesses.
The true God has witnesses because the true God speaks and acts. The witnesses are the people of God, and witnessing to God's reality is the chief mission of God's people. The audience for such witness is not God but the rest of the world that does not know or believe that the God of Israel is the one, real God. Radical monotheism--that the God of Israel is the only god that exists--is clear since there are no witnesses to any other god. There may be worshipers, but there are no witnesses, and the worshipers therefore worship in vain.
God's concern for witnesses is not only that these other gods be proved false but also that other nations learn that the God of Israel is true, and the only savior there is for any people (43:11). It is both for the judgment and redemption of those outside of Israel that the people of God need to carry out their task. Twice in these few verses we find the words: "You are my witnesses" (43:10, 12).
We find much the same theme in the New Testament. …