Summary: Jesus shows how to Confront an Evil World through presenting 1) A Clear Message (Matthew 10:7), and confidence of 2) Confirming Credentials (Matthew 10:8)
Matthew 10:7-8  And proclaim as you go, saying, 'The kingdom of heaven is at hand.'  Heal the sick, raise the dead, cleanse lepers, cast out demons. You received without paying; give without pay. (ESV)
A common practice in warfare is psychological operations, or Psych. Ops. Key to Psych. Ops. is to demonize the enemy. Over this past week while Lisa and I were in New Orleans, we had the opportunity to visit the WWII museum that was there. Among the exhibits they presented were WWII Psych. Ops. that each side undertook. For the Asia-Pacific war, both sides used propaganda in posters, music, and movies to inflame opinions and win hearts and minds. The Japanese played on resentment of Western colonization throughout Asia to portray themselves as liberators bent on creating a new, prosperous Asia free from Western control. Japanese propaganda depicted (Westerners) as beasts, vermin, or demons that threatened Japanese civilization and had to be destroyed. The racial stereotyping was so deeply engrained that American authorities embarked on an extensive propaganda campaign to distinguish between the "good" Asians (The Chinese allies) and the "barbaric" Japanese.
Our Lord, while acknowledging the reality of evil in this world, called his followers to distinguish between the Satanic forces, who are enemies of those who belong to the Kingdom of God, and a lost humanity that may be hostile to our efforts but are not our enemy. As they began to see the world as He sees it, looking out on lost humanity through their Lord’s eyes and with His heart of compassion, they also began to see that they themselves were called to go out and warn that lost world of the coming harvest of judgment and to invite them into the Lord’s kingdom.
This world is not a place of positive direction and affirmation. Lurking behind some outward tolerance, is real evil. Jesus demands that we not remain silent or impotent in the face of evil. The calling of every Christian is one to confront an evil world through the power of the Holy Spirit. All those who have the Holy Spirit within them through faith, and utilize the word of God, have all the tools they need. In explaining this, Jesus shows how to Confront an Evil World through presenting 1) A Clear Message (Matthew 10:7), and confidence of 2) Confirming Credentials (Matthew 10:8)
Jesus shows how to Confront an Evil World through presenting:
1) A Clear Message (Matthew 10:7)
Matthew 10:7  And proclaim as you go, saying, 'The kingdom of heaven is at hand.' (ESV)
Satan’s surest way of making the gospel impotent is simply to keep it from being understood. When the gospel is clouded with political, cultural, social, economic, environmental, ecclesiastical, and other such causes, its message is muddled and its power is diluted.
The word translated “proclaim/preach” here means to herald as a crier, “to make a public proclamation with such gravity, formality, and authority as must be heeded”. This style was not a mild-mannered (person) speaking in a mild-mannered way and giving a mild-mannered message (Butler, J. G. (2008). Analytical Bible Expositor: Matthew (177). Clinton, IA: LBC Publications). The action here is to proclaim/preach came to be used characteristically for the preaching of the gospel, but it cannot have that technical meaning here (Jesus had not yet died and risen). It means here the preaching of the same message as Jesus (Morris, L. (1992). The Gospel according to Matthew. The Pillar New Testament Commentary (246). Grand Rapids, MI; Leicester, England: W.B. Eerdmans; Inter-Varsity Press.)
The message is to be proclaimed “as you go;” as vv. 11–15 will make clear, this is to be an itinerant mission, not a settled ministry in one place (France, R. T. (2007). The Gospel of Matthew. The New International Commentary on the New Testament (383). Grand Rapids, MI: Wm. B. Eerdmans Publication Co.).
• To confront an evil world, means being ready to proclaim the realities of the gospel in every sphere that we travel. This world is not our home. We are all to be itinerant missionaries.
The message Jesus gave the apostles to proclaim/preach was simply stated: The kingdom of heaven is at hand. The message of God’s impending reign is most appropriate for those deemed “subjects of the kingdom” (8:12). The authority granted to them (10:1) enables them to exhibit the reality of God’s presence (Chouinard, L. (1997). Matthew (Mt 10:7–8). Joplin, MO: College Press.)
Please turn to Acts 3
In Scripture, the kingdom of heaven can be viewed in three aspects. First, it is manifest in conversion, when a person enters the sovereign rule of God by trusting in Christ for salvation (cf Matt. 18:3). Second, it is manifest in consecration, as believers live out the divine principles of God’s revelation by obedience to His Word. “The kingdom of God is … righteousness and peace and joy in the Holy Spirit” (Rom. 14:17). Third, the kingdom will be seen in its glorious consummation when Christ returns to earth to establish and rule it in person and then sets up His eternal kingdom (Matt. 25:31; Acts 3:19–21; Rev. 11:15; 20:4). Summed up, the kingdom is the reign of God … which will one day be consummated over all the earth. Although the disciples did not understand it yet, it began with the Incarnation of Christ (the Messiah) and will be consummated at the Second Coming of Christ.( Utley, R. J. (2000). The First Christian Primer: Matthew (Vol. Volume 9, p. 88). Marshall, TX: Bible Lessons International.)