An even mind should be preserved in adversity as well as in prosperity. However, evil things must be avoided.
186. There is also that true freedom of the mind from vexation which makes us neither give way too much in our griefs, nor be too elated in prosperity. And if they who urge men to undertake the affairs of the state give such rules, how much more ought we who are called to do duty in the Church, to act thus and do those things which are pleasing to God, so that Christ's power may show itself forth in us. We too must prove ourselves to our Captain, so that our members may be the weapons of justice; not carnal weapons in which sin may reign, but weapons strong for God, whereby sin may be destroyed. Let our flesh die, that in it every sin may die. And as though living again after death, may we rise to new works and a new life.
187. These, then, are the services of fortitude; and full they are of virtuous and seemly duties. But in all that we do we must look to see, not only if it is virtuous, but whether it is possible, so that we may not enter upon anything that we cannot carry out. Wherefore the Lord, to use His own word, wills us to flee in the time of persecution from one city to another; so that no one, whilst longing for the crown of martyrdom, may put himself in the way of dangers which possibly the weak flesh or a mind indulged could not bear and endure.