None is righteous, not one as all are lost apart from Christ...

Now some did not believe themselves guilty of actual sins in thought, word, and deeds.  I, and people like me in monasteries and religious communities, wanted to be monks and priests.  We fought against evil thought by doing such things as fasting, staying awake, praying, saying Mass, wearing coarse garments, and sleeping on hard beds.  In total sincerity and with great effort, we wanted to be holy.  Yet the heredity, inborn evil sometimes came out in sleep, as happens (St. Augustine and St. Jerome, among others, also confess this).  Still, each one held the other in high esteem.  According to our teaching, some monks were regarded as holy, without sin, and full of good works.  Also, since we had more good works that we needed to get to heaven, we could communicate and sell our good works to others.  This is actually true.  Seals, letters, and examples are at hand to prove that this happened.

These holy ones did not need repentance.  What would they repent of, since they had not indulged their wicked thoughts?  What would they confess about words they never said?  What should they render satisfaction for, since they were so guiltless that they could even sell their extra righteousness to poor sinners?  In the time of Christ, the Pharisees and scribes were these kinds of saints.

But here comes the fiery anger of St John, the true preacher of repentance.  With one bolt of lightning, he hurls together both those selling and those buying works.  He says:"Repent!" (Matthew 3:2).

John says, "Repent, both of you. You also penitents and false saints, both of you need the forgiveness of sins.  Neither of you know what sin really is.  Much less your duty to repent of it and shun it.  For no one of you is good.  You are full of unbelief, stupidity, and ignorance of God and God's will.  But He is present here, of whose "fullness we have all received, grace upon grace" (John 1:16).  Without Him, no one can be righteous before God.  Therefore, if you want to repent, repent rightly.  Your works of penance will accomplish nothing.  As for you hypocrites, who do not need repentance, you serpents' brood, who has assured you that you will escape the wrath to come and other judgments?" (Matthew 3:7; Luke 3:7).

In the same way Paul also preaches, "None is righteous, no, not one; no one understands; no one seeks for God.  All have turned aside; together they have become worthless; no one does good, not even one" (Romans 3:10-12).  And God now "commands all people everywhere to repent" (Acts 17:30).  "All people," He says. No one is an exception who is a human being.  This repentance teaches us to discern sin:  We are completely lost; there is nothing good in us from head to foot; and we must become absolutely new and different people.
~BOC, SA, III, III, 28-35