When Jesus Christ was sent by God the first time, it was for the purpose of being voluntarily sacrificed as a meek and humble "Lamb of God." When The Messiah returns however, it will be as an all-powerful, conquering "King of kings and Lord of lords" (Revelation 19:11-16). He will take possession of the earth from Satan (see That Old Serpent), the present "god of this world" (2 Corinthians 4:4, see The Lame Duck). The change of rule, which will ultimately result in true and permanent world peace, will itself not, unfortunately, be accomplished peacefully.
God's Wrath On A Sinful World
"Then I saw another angel flying in midheaven, with an eternal gospel to proclaim to those who dwell on earth, to every nation and tribe and tongue and people; and he said with a loud voice, "Fear God and give Him glory, for the hour of His judgment has come; and worship Him who made heaven and earth, the sea and the fountains of water."
"Another angel, a second, followed, saying, "Fallen, fallen is Babylon the great, she who made all nations drink the wine of her impure passion."
"And another angel, a third, followed them, saying with a loud voice, "If any one worships the beast [see The Antichrist and The Great False Prophet] and its image, and receives a mark on his forehead or on his hand, he also shall drink the wine of God's wrath, poured unmixed into the cup of His anger, and he shall be tormented with fire and sulphur in the presence of the holy angels and in the presence of the Lamb. And the smoke of their torment goes up for ever and ever; and they have no rest, day or night, these worshipers of the beast and its image, and whoever receives the mark of its name." Here is a call for the endurance of the saints [see What Is A Saint?], those who keep the commandments of God [see The Ten Commandments and The Ten Commandments Now?] and the faith of Jesus." (Revelation 14:6-12 RSV)
The Return Of Jesus Christ
"Then I saw heaven opened, and behold, a white horse! [see Two White Horses] He who sat upon it is called Faithful and True, and in righteousness He judges and makes war. His eyes are like a flame of fire, and on His head are many diadems; and He has a name inscribed which no one knows but Himself. He is clad in a robe dipped in blood, and the name by which He is called is The Word of God [see The Logos]. And the armies of heaven, arrayed in fine linen, white and pure, followed Him on white horses. From His mouth issues a sharp sword with which to smite the nations, and He will rule them with a rod of iron; He will tread the wine press of the fury of the wrath of God the Almighty." (Revelation 19:11-15 RSV) (see The Return Of Jesus Christ)
Fact Finder: Will the deceived nations of the world actually attempt to fight Jesus Christ at His Return?