A letter from John Calvin to William Rabot, July 14, 1550, a student of law at the University of Padua:
As I understand from your letter, that it is not very long since the Lord shed the light of His gospel on you, I could not give a fitter expression of my love towards you, than by exhorting and encouraging you to daily exercises. For we see sparks of piety immediately disappear which had shone forth on many occasions; because, instead of increasing the flame, they rather extinguish what little light the Spirit of God had enkindled in them, by the empty allurements of the world, or the irregular desires of the flesh. That nothing of this kind may happen to you, you must first of all give devoted submission to the will of the Lord, and in the next place, you must fortify yourself by His sacred doctrines.
Letters from John Calvin: Selected from the Bonnet Edition, the Banner of Truth, 1980, p. 118.