Amazing, every single word you just said was wrong
Just go ahead and say it was the Jews that killed Jesus. I know Nostrae Aetate has made that a booboo notion but it’s true. Jesus absolutely intended for his religion to rule the world. The Catholic Church is the Kingdom of Heaven for crying out loud, you think Jesus wanted it to stay underground forever? God willed its rise to flourishing power just as he took the nomadic slave driven Israelites and turned them into a might Kingdom. Of course God can diminish (though will never extinguish) the reach of the Church if her branches in a region do not produce good fruit. The Church has the absolute right to inform the morality of the civil government and the government has the duty of protecting the Church and the faithful. Most monarchs did live in a harmonious symphony with the Church, but we study the loud examples that were the exception (Henry VIII, Frederick II etc)
If there was never any symphony between Church and State, explain the Holy Roman Empire (you lose points if you quote Voltaire), Clovus I and the Merovingians, Carolus Magnus (Charlemagne) and his Grandfather and the Carolingians, the Hapsburgs, the Bourbans, etc. There was magnificent symphony between the two, you’re simply stuck in the modern day liberal frame of discourse.