A letter of encouragement from John Calvin, to Thomas Cranmer, who was active in the work of reformation of the Church of England, July, 1552:
Assuredly pure and undefiled religion will never flourish, until the Churches shall have been at greater pains to secure suitable pastors, and such as shall conscientiously discharge the duties of teaching. Satan, indeed, opposes his secret wiles to the accomplishment of this.
Letters from John Calvin: Selected from the Bonnet Edition, the Banner of Truth, 1980, pp. 141-42.