"God said, 'This is that sin which is never forgiven, now or ever: the refusal, the scorning, of my mercy. For this offends me more than all the other sins they have committed. So the despair of Judas displeased me more and was a greater insult to my Son than his betrayal had been.'" -St. [...]
"If only everyone weak and imperfect like me felt as I do, no one would despair of reaching the heights of love, for Jesus does not ask for glorious deeds. He asks only for self-surrender and for gratitude." Source: St. Therese of Lisieux, The Story of a Soul, Saint Benedict Press, 2010.
"Today millions of men and women consider that their happiness is destroyed if they must get along without a few things of which their grandfathers had never dreamed. Luxuries have become necessities to them; and the more things a man needs in order to be happy, the more he has increased his chances of disappointment [...]
"We ought to be on our guard, in case our conscience has stopped troubling us, not so much because of its being clear but because of its being immersed in sin. A proof of our having been delivered from our failings is the unceasing acknowledgement of our indebtedness. Nothing equals the mercy of God or [...]
"For this sin of ultimate despair is much more displeasing to me and harmful to them than all the other evils they have committed. And this is why: Other sins are committed with some selfish sensual pleasure, and sometimes they are regretted, and they can be regretted in such a way that the regret will [...]