Watch out!

"In the spiritual life, I can promise myself nothing without the special help of God . . . From one moment to another, I may fall into mortal sin: consequently, even though I may have labored many years in acquiring virtues, I may in one instant lose all the good I have done, lose all my merit for eternity, and lose even that blessed eternity itself. How can a king rule with arrogance when he is besieged by his enemies and from day to day runs the risk of losing his kingdom and ceasing to be a king? And has not a saint abundant reasons, from the thought of his own weakness, to live always in a state of great humility, when he knows that from one hour to another he may lose the grace of God and the kingdom of Heaven, which he has merited by years of laboriously acquired virtues? 'Unless the Lord build the house, they labor in vain that build it' (Ps. 126:1). However spiritual and holy a man may be, he cannot regard himself as absolutely secure. The Angels themselves, enriched with sanctity, were not safe in Paradise. Man, endowed with innocence, was not safe in his earthy paradise. What safety, therefore, can there be for us with our corrupt nature, amid so many perils and so many enemies who within and without are ever seeking insidiously to undermine our own eternal salvation? In order to be eternally damned, it is enough that I should follow the dictates of nature; but to be saved, it is necessary that divine grace should prevent (go before) and accompany me, should follow and help me, watch over me and never abandon me. Oh, how right therefore was St. Paul in exhorting us to 'work out our salvation'—which is for all eternity—'with fear and trembling' (Phil. 2:12)."

— Fr. Cajetan da Bergamo, Humilty of Heart, p. 21-22