In the United States many churches display the American flag. The Christian flag is usually put on one side and the American flag on the other. Does having the two flags in your church mean that Christianity and the American establishment are equal? If it does, you are really in trouble. These are not two equal loyalties. The state is also under the norm of the Word of God. So if by having the American flag in your church you are indicating to your young people that there are two equal loyalties or two intertwined loyalties, you had better find some way out of it. The establishment may easily become the church’s enemy. Before the pressure comes, our young people (from kindergarten on), our older people, and our officers must understand this well: there are not two equal loyalties; Caesar is second to God. This must be preached and taught in sermons, Sunday school classes, and young people’s groups.
It must be taught that patriotic loyalty must not be identified with Christianity. As Christians we are responsible, under the Lordship of Christ in all of life, to carry the Christian principles into our relationship to the state. But we must not make our country and Christianity to be synonymous. —Francis Schaeffer, The Church at the End of the Twentieth Century