Legitimate authority can be a tough sell, especially in these cynical times. We can easily identify with a time and place where legitimate religious authority was being challenged by a secular religious authority. John lays it out perfectly for us.
I know it will be said that a priest ordayned by authority derived from the See of Rome is, by the Law of the Nation, to die as a Traytor, but if that be so what must become of all the Clergymen of the Church of England, for the first Church of England Bishops had their Ordination from those of the Church of Rome, or not at all, as appears by their own writers so that Ordination comes derivatively from those now living.
-- From his speech on the scaffold