Knowing the exact nature of everything, God permits each person to be tested according to his strength. As St. Paul puts it: 'God is to be trusted not to let you be tried beyond your strength, but with the trial He will provide a way out, so that you are able to bear it' (1 Cor. 10:13).
Not he is chaste in whom shameful thoughts stop in time of struggle, work and endeavor, but he who by the trueness of his heart makes chaste the vision of his mind not letting it stretch out towards unseemly thoughts.
When tested by some trial you should try to find out not why or through whom it came, but only how to endure it gratefully, without distress or rancor.