The apostle Paul said in Ephesians 6:19-20, “Pray also for me, so that when I open my mouth, words may be given me so that I will fearlessly make known the mystery of the gospel, for which I am an ambassador in chain. Pray that I may fearlessly declare it, as I should.” Evangelism is spiritual warfare. Evangelism is winning souls into the kingdom of God and thus spiritual warfare. Without the power of the Holy Spirit, evangelism is impossible. Jesus said in Acts 1:8, “You will receive power when the Holy Spirit comes on you; you will become my witness in Jerusalem, and in Judea and Samaria, and to the ends of the earth.” The reason why evangelism is impossible without the power of the Holy Spirit is because it is not a war against flesh and blood but against the spiritual forces of evil in the heavenly realms. The apostle Paul describes the spiritual status of unbelievers in II Corinthians 4:3-4, “And even if our gospel is veiled, it is veiled to those who are perishing. (4) The god of this world has blinded the minds of unbelievers, so that they cannot see the light of the gospel of the glory of Christ Jesus, who is the image of God.” Therefore, without casting out the god of this world from the minds of unbelievers, evangelism is impossible, because he is blinding the minds of unbelievers so that they cannot see the light of the gospel of the glory of Christ Jesus. Jesus said in Matthews 12: 29, “Or again, how can anyone enter a strong man’s house and carry off his possessions unless he first ties up the strong man? Then he can rob his house.” Unless you tie a strong man, the owner of a house, you cannot enter it and carry off his possessions. Here a strong man is the god of this world. A house is an unbeliever. The god of this world is an owner of unbelievers. He is blinding unbelievers so that they cannot see the light of the glory of the gospel. Therefore, first you should tie him by the power of the Holy Spirit and then rob him of his possessions, unbelievers. You should fight against him by the power of the Holy Spirit and then win the souls of unbelievers into the kingdom of God. This is the reason why the apostle Paul asks the Corinthian believers to pray for him, so that whenever he opens his mouth, words may be given him so that he will fearlessly make known the mystery of the gospel to unbelievers.