The first time Jesus came to Earth was to preach the truth and die for our sins by providing a way that mankind would be able to get to Heaven. When Jesus returns it will be to destroy the wicked and to judge the living and the dead. It is Jesus' job to judge the world in righteousness. Jesus is also returning for His children, and to do away with sin. After Jesus returns then the Earth will be destroyed and there will be a new Heaven and a new Earth. And God's people will live forever in paradise.