5 What then? Some one will say. We have been beguiled and are lost. Is there then no salvation left? We have fallen: Is it not possible to rise again? We have been blinded: May we not recover our sight? We have become crippled: Can we never walk upright? In a word, we are dead: May we not rise again? He that woke Lazarus who was four days dead and already stank, shall He not, O man, much more easily raise you who art alive? He who shed His precious blood for us, shall Himself deliver us from sin. Let us not despair of ourselves, brethren; let us not abandon ourselves to a hopeless condition. For it is a fearful thing not to believe in a hope of repentance. For he that looks not for salvation spares not to add evil to evil: but to him that hopes for cure, it is henceforth easy to be careful over himself. The robber who looks not for pardon grows desperate; but, if he hopes for forgiveness, often comes to repentance. What then, does the serpent cast its slough, and shall not we cast off our sin? Thorny ground also, if cultivated well, is turned into fruitful; and is salvation to us irrecoverable? Nay rather, our nature admits of salvation, but the will also is required.
Source: Catechetical Lectures (New Advent)