When the Lord asks who shall go for them, Isaiah quickly answers, “Here am I. Send me,” so what does this message mean to us today?
Who Shall Go?
When Isaiah “heard the voice of the Lord saying, “Whom shall I send, and who will go for us” (Isaiah 6:8a), it seems to imply that there must have been a shortage of men who were willing to go for the Lord. Apparently there wasn’t a line waiting for men to go for the Lord. That may be because God told Isaiah, in advance, that they would reject His message and not listen to the Word from the Lord. Still, God tells Isaiah to go, even though they will “Keep on hearing, but do not understand; keep on seeing, but do not perceive” (Isaiah 6:9). Jeremiah the Prophet heard much the same thing. God told Jeremiah to go to Judah but told him that they will reject you and My message. It didn’t matter; God still commanded Jeremiah to “speak all these words to them, but they will not listen to you. You shall call to them, but they will not answer you” (Jer 7:7). Just because they would reject Isaiah and Jeremiah’s messages doesn’t get them off the hook from going. Thankfully, they did go, even though Jeremiah is like most of the prophets God called, reluctantly (Jer 1). To be clear, the one who is sent by the Lord on a divine mission must be a person that is willing to “go” for the Lord, having a heart compelled to bear the message, especially a message that most will reject and/or hate. 
Who to Send?
Isaiah was hesitant to go for God because he saw himself as a man of unclean lips, so only after the Lord cleanses his tongue will Isaiah feel qualified to “go” for the Lord. After Isaiah’s lips are touched by the hot coal he responds to the “Whom shall I send, and who will go for us” (Isaiah 6:8a) with one of the most beautiful statements of obedience found in Scripture. Who will go for “us” shows the Trinity is involved here and They are unanimous in Their will. God asked Isaiah, and He asks all believers today, “Whom shall I send, and who will go for us” (Isaiah 6:8a). Will you say as Isaiah the Prophet said, “Here am I. Send me” (Isaiah 6:8b).
Few to Send
The “great commission” given to the disciples and to all believers has become the great omission in many churches today. Less than 1 in 10 believers regularly share their faith; even less have ever led someone to Christ. Most people are reluctant, just like Isaiah and Jeremiah were, mainly because they know people will not receive the gospel very easily. One thing I’ve learned; the truth sets you free…or it makes you really mad. Jesus asked the disciples to pray to the Lord of the Harvest that He might send forth more laborers to enter into the harvest, saying, “pray earnestly to the Lord of the harvest to send out laborers into his harvest” (Matt 9:38). Why did Jesus want them to pray for more laborers? Clearly the harvest was too large for the few laborers that were available, and it’s still true today! There’s a labor shortage…a labor shortage of workers willing to enter into the harvest. It’s made more difficult to find laborers because most people understand that they will reject their message!
Where to Go
Most people think of missionaries that are in far-flung places like Africa, Asia, or South America, but there’s a mission field right where you live. There are a lot of people you know; co-workers, retirees, friends, family, neighbors and acquaintances, who still don’t know Jesus Christ as Lord and Savior. They might know about Him, but they need to know Him in a personal relationship. Even where you live there is a huge field to enter into, so why not you? Why shouldn’t God send you as one among the laborers of the harvest?
Fear of Man
Perhaps the greatest reason people don’t “go” for the Lord and share Christ is because of the fear of man is stronger than their fear of God. To fear the Lord means to obey the Lord and to treat His Word and Name as holy and reverential. If we’re more afraid of what people might think than what God thinks, then we’ve not really thought about their eternal destiny (Rev 20:12-15). That means, we’ll be silent before others. No wonder “The fear of man lays a snare, but whoever trusts in the LORD is safe” (Prov 29:25). In Jesus’ day, “many even of the authorities believed in him, but for fear of the Pharisees they did not confess it, so that they would not be put out of the synagogue” (John 12:42). They were more concerned with what people thought than what they knew to be true! How sad. If we deny Christ in public, then He will also deny us before God the Father (Matt 10:33). 
It grieves me to say this, but most believers will not go because of their fear of man or fear of upsetting people, but we must be honest; the gospel will offend people. We must face up to the fact that our message, “to one a fragrance from death to death, to the other a fragrance from life to life” (22 Cor 2:16), but isn’t that worth the risk of offending someone? Can’t we see their future without Christ as motivation to warn them of the wrath to come (2 Thess 1:9)? When we all get into the Kingdom, I don’t think well say, “I wish I hadn’t embarrassed myself by sharing Christ with my aunt,” but rather we might regret not telling many more about Christ than we did while on earth. God could have snatched us up to heaven the moment we were saved, but we’ve got work to do, and that work is a harvest. One so large, we’re going to need help…your help! Are you willing to “go” and enter into the harvest, even though they will scorn you, reject you, and maybe even hate you? But then think about this; wasn’t someone willing to take that risk for you? Aren’t you glad they did!?
Here is some related reading for you: How Can You Revive Evangelism in Your Church? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.