Yes, some day the prayer Jesus taught His disciples will be fulfilled: "Thy kingdom come, Thy will be done in earth, as it is in heaven" (Matthew 6:10, KJV).
But this will only happen when Christ comes again to establish His Kingdom (or rule) of perfect peace and justice. When He comes again, all the evils and horrors of this world will be conquered, and the Prince of Peace will rule in glory and power and perfection. In that day, the Bible says, "The wolf and the lamb will feed together, and the lion will eat straw like the ox. ... They will neither harm nor destroy" (Isaiah 65:25).
We can barely imagine a world like that - a world in which God's will is followed as perfectly on earth as it is in heaven. But some day it will happen! God's plan is to bring about "a new heaven and a new earth, the home of righteousness" (2 Peter 3:13). Some day, Satan will be bound, and peace will rule over the earth. This is what the Bible calls "the blessed hope - the glorious appearing of our great God and Savior, Jesus Christ" (Titus 2:13).
Does this mean we should just give up, and not bother trying to make the world a better place or telling others about Christ's salvation? No, not at all. Yes, some day Christ will come again - but until that day, do all you can to serve Him and live for Him. Is He the center of your life?