"For our citizenship is in heaven, from which we also eagerly wait for the Savior, the Lord Jesus Christ" (Philippians 3:20). "Now, therefore, you are no longer strangers and foreigners, but fellow citizens with the saints and members of the household of God" (Ephesians 2:19).
As far as God is concerned, there is no such thing as dual citizenship. There cannot be loyalty to both sides of a conflict, and there is conflict between Satan and God. There is no neutral ground, and we must choose our captain--to whom we will pledge allegiance. Since the heavenly kingdom has one King, and the earthly kingdom another, we cannot be loyal to both. We must choose.
If we try to maintain friendship with both rulers, and keep peace where there is no peace, we will find ourselves torn apart in the conflict. We will always be at odds. No man can serve two masters, and those who try don't please anybody. The only way we can please God is to separate ourselves from the kingdom of darkness and come under the rule of God.
If we try to live in both kingdoms, we will compromise. Compromise always brings weakness. God does not compromise, and He never asks us to compromise. God works from a place of absolute strength, with absolute standards of holiness and righteousness. The kingdom of this world is based on compromise, with the laws approximately representing the standards of the majority. The laws shift with the shifting standards of the people. What is not acceptable today becomes acceptable tomorrow. Worse than that, the religious system is only one step behind the world.
Because so many want to maintain a place of acceptance in the world, they find a way to justify a lower standard which is just a bit different from that of the world. In so doing, many feel they are promoting righteousness and standing on God's side. But the righteousness that is being promoted is only a certain standard of outward actions which has no meaning to God. That was what the Law of Moses was, but the Law was also put away at Calvary. The only righteousness that has any meaning is that which comes from the heart, and that is something that only God can do.
Many examples could be given, but the words of Jesus in Matthew are enough: "You have heard that it was said to those of old, 'You shall not commit adultery.' But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart" (Matthew 5:27,28). The righteousness that God brings into the heart by His presence has an outward expression, but expression put on the outside, whether in pretense or forced, has no value to God. On the contrary, it may actually be easier to deal with sin if it is open rather than hidden.