Some modern critics argue that Jesus' phrase "Render unto Caesar what is Caesar's, and unto God what is God's" favors the modern political concept of separation of church and state.

This assumes a modern paradigm entirely foreign to the text. In Jesus' day, the main political body was a religious one -- the Sanhedrin -- and Caesar himself was associated with the imperial cult of Rome. There was NO separation of church and state in antiquity. That statement was, contextually, the separation of 'church' (the local state religion) from 'church' (the imperial Roman state religion).