Ioannis Vvolphii Tigurini De officio praeconis evangelici oratio, qua D. Pauli 2. Timoth. 2. locus explicatur, Stude teipsum probatum exhibere Deo, operarium non erubescendum, recte secantem sermonem veritatis

And the more difficult and arduous those things we have undertaken to perform are, the greater need there is for the heat and movement of the mind. For this reason, Paul thinks that since it is the most difficult thing of all to reduce from vice to virtue, from the allurements of worldly pleasures to the contemplation and study of celestial joys, from crimes to honest actions, from error to truth: it is the duty of the evangelical herald to be himself immune from these defects and vices before everyone else, and to have progressed to at least some proficiency of mind, and to incline and lean of his own accord toward that to which he drives others. For with what arguments will he, who himself is a stranger to all justice, lead us so that we do not harm anyone, so that we render to each his own, and so that we serve the common utility? Who will teach me the choice between good and evil, if he is endowed with no prudence? And how shall I learn from him to fear nothing, to despise all human things, and to think nothing that can happen to a man on account of Christ is intolerable, if I see him himself avoiding labors and dangers and fearing every pain?