In a society or state with hundreds of different religions or institutions of religion, the state should be neutral, not favoring one sect or religion over others. Nor can it endorse one religion or all religions as if all are of value to the state and expected to conform to the current patriotism. A church or denomination which is not truly free from government support or endorsement is not free to criticize and therefore correct unjust government or secular leadership. It is always possible that Christians may decide to resist bad laws or to resist the state's intervention in religion or its demands for political support. Jesus' idea of the kingdom of this world as being different from the kingdom of God is eternally valid.
Separation is essential to permit voluntarism to flourish.
It is essential also to recognize that God is not a tribal or national god. Christianity has a world mission that is compromised by or suffers from identification with one nation's military occupation of other nations, or with a nation's unjust laws or lack of respect for human rights. Separation prevents the government from determining church policy, whether directly or indirectly. Separation does not permit churches to seek special privileges from government that are denied to minority religious groups and to non-religious citizens. Churches are healthier and stronger if they assume responsibility both for financing their own programs and for stimulating their members to accept that responsibility.