Isaiah 6 presents the Lord’s commissioning of Isaiah. He saw a vision of the Lord on His throne (6:1-4). His response to the vision (6:5) led to a seraphim’s acting to consecrate him for his commission by dealing with his iniquity and sin (6:6-7).
Isaiah then heard the Lord say, “Whom shall I send, and who will go for us?” (6:8a). He responded by volunteering himself to be sent by the Lord (6:8b). The remaining verses in the chapter relate the details of his commissioning (6:9-13).
Preachers have used Isaiah 6:1-8 to challenge believers to be involved in evangelism and missions. Based on what I can recall from my experience, they have not treated his actual commission (6:9-13) much at all in those messages. Treating the passage in that manner may have resulted in obscuring important understanding for many believers because of what the rest of the passage teaches Isaiah’s commission actually was.
The Lord accepted Isaiah’s volunteering himself and directed him to go communicate His message to His people (6:9a). He was to tell them, “Hear ye indeed, but understand not; and see ye indeed, but perceive not” (6:9b). His mission also included that he was to “make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed” (6:10).
These statements show that Isaiah’s mission was hardly an evangelistic one in the traditional sense. Rather, Isaiah was being sent as an agent of God who would not bring about their turning to the Lord—he would actually serve to harden them so that they would not see, hear, understand, convert, and be healed.
The ensuing dialogue between Isaiah and the Lord confirms this interpretation (6:11-13). Isaiah asked, “Lord, how long?” (6:11a). The Lord responded, “Until cities be wasted without inhabitant, and the houses without man, and the land be utterly desolate, and the Lord have removed men far away, and there be a great forsaking in the midst of the land (6:11b-12). Isaiah was thus informed that the hardening would continue until there would come about a great destruction among His people. God, however, did provide him with some hope by telling him that there would be a tenth who would be a remnant, who would yet suffer judgment themselves, but from whom also there would yet be “the holy seed” (6:13).
This analysis suggests that preachers should not use Isaiah 6 to challenge believers about evangelism and missions without at least some explanation of what Isaiah’s actual commission was. By at least briefly explaining the original sense of the passage, the preacher who chooses to use Isaiah 6 to challenge contemporary believers will be less likely to promote his audience’s having a superficial understanding of or even a total lack of awareness of the original significance of the passage as a whole.