Zac Poonen emphasizes the importance of having a vision of God's holiness and grace as illustrated in Isaiah 6, where Isaiah responds to God's call with 'Here am I. Send me.' He stresses that true service to God must come from being sent by Him, rather than from human initiative, and that the Holy Spirit guides us today in a similar way. Poonen highlights that while the call may be difficult, it is essential for producing lasting fruit in God's kingdom. He encourages believers to seek God's voice in their hearts and to understand their commission, even when it may seem challenging or unfruitful.

In Chapter 6 of Isaiah, Isaiah had a vision of both the throne and the altar here. Then the Lord asks, "Whom shall I send? Who will go for us?" (Isaiah 6:8). Isaiah replies, "Here am I. Send me." We need to see both the throne and the altar constantly. We need to be struck down to the dust first with a vision of God's holiness, and then we need to be lifted up because the blood from the altar has cleansed us. Only then can we go forth and serve the Lord. We can't go forth if God doesn't send us. If we go without God sending us, then we will labour in vain. Many "Christian workers" have not been sent by God. Some organisation or man has sent them to the mission field. Or perhaps they have gone on their own. It is easy to engage in Christian activity because the need is so great. But if we want fruit that lasts for all eternity, God Himself must send us. Other godly men may confirm the call we receive from God - butthey cannot call us. God called Saul and Barnabas personally to His service. The confirmation of that call came later through other prophets (Acts.13:1-4). And when God calls us, He will also tell us what to preach. He told Isaiah, "Go. Tell this people……." (Isaiah 6:9). God is still the same today as He was in Isaiah's time. Under the new covenant, the Holy Spirit dwells in our hearts and so we don't hear God with our physical ears now, as Isaiah heard Him then. We hear His voice today in our hearts. But His voice is just as unmistakable. I have never heard the Lord's voice audibly with my physical ears and I have never seen Him or an angel with my physical eyes. But I have seen Him and heard Him clearly in my heart many times during the last five decades. Jesus said that those who believed in Him without seeing Him with their physical eyes are actually more blessed than those who see Him and believe (John 20:29). The commission that the Lord gave Isaiah was a very difficult one. He told him, "Go and tell my people this: 'Though you hear my words repeatedly, you won't understand them. Though you watch and watch as I perform my miracles, still you won't know what they mean.' Dull their understanding, close their ears, and shut their eyes. I don't want them to see or to hear or to understand, or to turn to me to heal them" (Isaiah 6:9,10) . This is the verse that Jesus quoted when He was explaining why He spoke to people in parables (Matt.13:15). So what do we see here? A vision of God, a vision of self, a vision of grace that forgives, a vision of anointed service, and finally, a vision of fruit (Isaiah 6:13). A holy seed would come forth from the corrupt nation of Judah. A remnant will be raised up for the Lord through our service.