What's the relationship between church and nation?

How would you describe the he relationship between church and nation from the biblical view?

I think Jesus answered that question quite clearly:

Matthew 22:15-22 Common English Bible (CEB)
15 Then the Pharisees met together to find a way to trap Jesus in his words. 16 They sent their disciples, along with the supporters of Herod, to him. “Teacher,” they said, “we know that you are genuine and that you teach God’s way as it really is. We know that you are not swayed by people’s opinions, because you don’t show favoritism. 17 So tell us what you think: Does the Law allow people to pay taxes to Caesar or not?”

18 Knowing their evil motives, Jesus replied, “Why do you test me, you hypocrites? 19 Show me the coin used to pay the tax.” And they brought him a denarion. 20 “Whose image and inscription is this?” he asked.

21 “Caesar’s,” they replied.

Then he said, “Give to Caesar what belongs to Caesar and to God what belongs to God.” 22 When they heard this they were astonished, and they departed.

We pay taxes to the government, we show respect to our leaders because they are put in positions of authority, not because they are outstanding or even likable people, we do our part as citizens of our nation. Other than that, everything we are, being stamped with the image of God in our creation, belongs to God.