As long as God has morally sufficient and justifiable reasons to allow harm He does nothing wrong in allowing it. Those in hell have their hearts separated from God’s mercy as Christ says depart from me. As a result their hearts harden. They loathe God and His children. They don’t want Him. If they don’t want to love God they don’t have to. But God is never obligated to give someone who hates Him and His children and don’t want to have anything to do with Him the gift of grace. The longer one is in hell the more wicked they become and the more just the punishment is. What God is mainly doing by keeping evil God haters out of the new creation is protecting His holy children from the contamination and harm of evil. God therefore has a morally sufficient and justifiable reason for hell. In all likelihood there’s infinitely many more reasons seeing that God is infinite in wisdom in knowledge and logical explanations are infinite in number. The new heavens and earth is created new and reconciled as all things are made new. The whole world that is fore loved and predestined worship God and love each other because they want to. Having all desire for sin removed from their hearts they become like God in that it is impossible for them to sin. They chose what they most want - God. This is freedom. Every knee bows in heaven, earth, and those saints resurrected from under the earth. The Hebrew phrase “Heavens and Earth” means “all things”. These are the all things reconciled. The nations and the kings of the nations are those in the new Heavens and Earth. The new city of Jerusalem is the center of the new universe. The lake of fire isn’t included in “all things made new.” or the “whole world.”
As we can see the “all things made new” is separated by the word “but” and then it goes on to describe those in the lake of fire separating the lake of fire from the new city and the new heavens and earth which is where the new city is located. The city or new Jerusalem isn’t the new heavens and earth. It’s only a small fraction of the new heavens and earth. The gates of the city are open for the nations in the new heavens and earth. Not the lake of fire even though that’s also outside the gates.