Look around you. Read the newspapers. Watch the evening news. Much of the misery in the world even today comes from church states and state churches. Separation of church and state has been good for the church, good for the state.
Some people enjoy distorting the doctrine.
Some dolts can not seem to face the facts. Jerry Falwell, Pat Robertson, and D. James Kennedy continue to call church-state separation a myth. Church and state have distinct constituencies in America. If you were born in Sweden you were automatically a Lutheran. Nothing like that obtains in this land.