_Be sober._ To be sober is of service outwardly to the body, and is the chief work of faith. For though a man has been justified, he still is not secured from evil lusts; faith has indeed begun to subdue the flesh, but this is ever bestirring itself, and likewise running riot in all sorts of lusts, which would gladly break forth again and act after their own will. Therefore the spirit must daily work to restrain and subdue it, and must charge itself therewith, without intermission, and have a care of the flesh that it do not destroy faith. Therefore those persons deceive themselves, who indeed say they have faith, and imagining that this is enough, live thenceforth according to their own caprice. Where the faith is genuine it must control the body and hold it in check, so that it shall not do what it lusts after. Therefore St. Peter says that we should be sober. Yet he would not have us destroy the body or weaken it too much, as we find many do who have fasted and tortured themselves to death. St. Bernard, even, continued for a long time in this folly, although he was truly a holy man, for he mortified his body to such an extent that his breath was offensive and could not be endured. Yet he afterwards forsook it, and charged his brethren that they should not inflict injury upon the body; for he saw very well that he had rendered himself unfit to be of service to his brethren. Therefore St. Peter requires nothing more than that we should be sober,--that is, mortify the body to such an extent as to prevent its being in our apprehension too wanton; for he fixes no definite time how long we should fast, as the Pope has done, but leaves it to each, individually, to fast so that he remain sober and do not burden the body with gluttony, to the end that he remain in possession of reason and reflection, and consider how far it is necessary for him to hold the body in check. For it is utterly idle to impose one and the same command upon a whole congregation and church, since we are so unlike one to the other; one strong, another weak in body,--so that one must mortify it more, another less, provided the body is to remain sound and in the best state for exertion.