The Church is not American
Every year when July 4th rolls around, the American church amps up their patriotism, further fusing two things that could not be more opposite: the beautiful, sacrificial Kingdom of God and the vengeful, bloody kingdom of the world.
Jesus is the clearest picture of what God is like and he is beautiful. In the Gospels his heart broke for those who were oppressed, he rebuked those who abused their power and he loved the unloved (he even loved his enemies!).
America does not operate that way.
America has done some amazing things, but throughout its history, people have been oppressed and blood has been shed to protect its interests. Describe America however you want, but it's definitely not Christian, or "Christ-like."
When American churches start fusing nationalism with the distinct beauty of God's Kingdom (from seemingly innocent statements like "God Bless America" to insane things like saying God rejoices in someone's murder), it sets up an ugly and completely inaccurate view of God. I may think of America as a great place filled with opportunity and blessed by God, but many folks don't see it that way. God "blesses" America? Really? American Indians and African Americans are just two of many communities that have been on the violent end of God "blessing" America.
The Church is not American (or any nationality for that matter). The Church is made up of all who strive to live like Jesus. The one and only allegiance The Church has is to Jesus. Its one and only call is to advance his Kingdom, by loving and serving its enemies.
Remember where your true allegiance lies.