There is no New Testament basis for a linking of church and state until Christ, the King returns. The whole "Constantine mentality" from the fourth century up to our day was a mistake. Constantine, as the Roman Emperor, in 313 ended the persecution of Christians. Unfortunately, the support he gave to the church led by 381 to the enforcing of Christianity, by Theodosius I, as the official state religion. Making Christianity the official state religion opened the way for confusion up till our own day. There have been times of very good government when this interrelationship of church and state has been present. But through the centuries it has caused great confusion between loyalty to the state and loyalty to Christ, between patriotism and being a Christian. We must not confuse the Kingdom of God with our country. To say it another way: "We should not wrap our Christianity in our national flag.
Francis A. Schaeffer, A Christian Manifesto
apologetics, christianity, church-and-state, history