From some articles I liked-
Our True Citizenship
When we submit to our Lord and become his disciples we become citizens of the kingdom of God, with heaven as our home. National interests are replaced by kingdom interests.
“Dear friends, I urge you, as aliens and strangers in the world, to abstain from sinful desires, which war against your soul.” (1 Peter 2:11)
“If the world hates you, keep in mind that it hated me first. If you belonged to the world, it would love you as its own. As it is, you do not belong to the world, but I have chosen you out of the world. That is why the world hates you.” (John 15:18-19)
Jesus prayed for his disciples: “I have given them your word and the world has hated them, for they are not of the world any more than I am of the world. My prayer is not that you take them out of the world but that you protect them from the evil one. They are not of the world, even as I am not of it.” (John 17:14-16)
“Jesus said, ‘My kingdom is not of this world. If it were, my servants would fight to prevent my arrest by the Jews. But now my kingdom is from another place.’” (John 18:36)
“Their mind is on earthly things. But our citizenship is in heaven. And we eagerly await a Savior from there, the Lord Jesus Christ, who, by the power that enables him to bring everything under his control, will transform our lowly bodies so that they will be like his glorious body.” (Phil 3:20-21)
“Do not love the world or anything in the world. If you love the world, love for the Father is not in you. For everything in the world - the cravings of sinful people, the lust of their eyes and their boasting about what they have and do - comes not from the Father but from the world. The world and its desires pass away, but whoever does the will of God lives forever.” (1 John 2:15-17)
“All these people were still living by faith when they died. They did not receive the things promised; they only saw them and welcomed them from a distance. And they admitted that they were aliens and strangers on earth. People who say such things show that they are looking for a country of their own. If they had been thinking of the country they had left, they would have had opportunity to return. Instead, they were longing for a better country — a heavenly one. Therefore God is not ashamed to be called their God, for he has prepared a city for them.” (Heb 11:13-16)
“For here we do not have an enduring city, but we are looking for the city that is to come.” (Heb 13:14)
Think of yourself as a missionary in a foreign land. And if you reflect on the fact that your existence will continue beyond trillions of millennia, the importance of a transitory kingdom of the world diminishes significantly.
“But you are a chosen people, a royal priesthood, a holy nation, a people belonging to God, that you may declare the praises of him who called you out of darkness into his wonderful light.” (1 Peter 2:9)
The “one nation under God” is the kingdom of God, and it is In God We Trust, not the weapons of the world (2 Cor 10:3-4).