This begs for research into what is a true church. A true church must focus its attention fully on Jesus Christ. Jesus often called himself the Son of Man which brings to mind the Man Child in Isaiah 66:7-8 as the children of Zion, the church Jesus was building by his earthly ministry. Various leaders created their own churches to promote the ministry of Paul or themselves but did not engage in practicing Jesus' own church, at best only pointing to Jesus. To have world peace we must replace false beliefs with Jesus' absolute truth.
There are several problems in converting the world while maintaining free will. One problem is mood swings. Many people will be for Jesus one moment but in another moment fight against Him or call his words fake. How does one fix that? Which will should be free? I believe that is why Jesus will allow those who choose Him to live with His rewards while letting those who choose evil to get worse and worse until they let Satan lose after 1000 years of freedom and try to fight against Jesus' people. They of course will be hurting the good people so God will act to end the evil.
So we who are good, pursuing Jesus faithfully in this age will be taken up before the Great Tribulation and be given the job of casting Satan down out of heaven, then other work that comes from obeying Jesus like preparing for the marriage feast of the lamb, helping to rapture those worthy to acend as Jesus returns, and building the New Jerusalem which comes down from heaven after 1000 years. Do you want heavenly work like that or just to be of this world? See theManChild.org