Jesus pointed out the sins many times throughout the Gospels, and it was not just those of the hypocritical Pharisees, as many modern-minded types would have us believe. I know many of both extremes, those for whom the pope himself is not Catholic enough, and who appear to claim the authority to oversee his excommunication, and those for whom the only mortal sin is to call something widely accepted in the culture a sin. Since I have had my share of personal showdowns with the former, and since the latter are much more abundant in the world, I want to focus more on the latter, and to unpack the meaning and depth of the word "mercy," especially in the context of God's divine mercy.
Dictionary.com has several definitions of the word, but the first entry defines mercy as "compassionate or kindly forbearance shown toward an offender, and enemy, or other person in one's power; compassion, pity, or benevolence." Let's face it now and admit we are all offenders against God, sinners, violators of His commands. If we claim we are not, then we lie and call God a liar, as the First Letter of John points out. As sinners, we are in need of repentance, which is more than just being sorry for our sins, but in its Greek origins means to turn around. All three of the synoptic Gospels quote Jesus as saying He has come to call sinners to repentance, not to deny their sins or say they're no big deal.
Jesus did not make any claim in John 8 that the woman caught in adultery was innocent, or that her sin did not matter. Yet we know the Pharisees wanted to use the opportunity to trip Him up. The Mosaic Law did call for the stoning of those involved in adultery, but under Roman occupation, as revealed later in the Passion narratives, the Jewish people did not have the right to put a person to death. It is Jesus, however, who trips them with their own legalistic obsessions, calling for the one without sin to cast the first stone. After the crowd leaves, with no one to condemn the woman, Jesus assures her that He does not condemn her either, and leaves her with the command, "Go and sin no more."
But it was Jesus Who was pointing out people's sins and telling them to repent. He's God, and therefore sinless, so He's allowed, while we have to keep our mouths shut about others' sins, right? Wrong! Jesus tells us to rebuke our sinful brethren (Luke 17:3 and Matthew 18:15). While still in His earthly ministry, He sends His disciples out two by two, healing the sick, driving out demons and calling for repentance. This continued after Pentecost, when Peter, filled with the Holy Spirit, called on the people to repent of their sins after their denial of Jesus. Was this because he was sinless? Absolutely not. Peter denied Jesus three times on the day of His Passion. Still, Peter used some tough words with the people, despite his own sins and betrayal of Jesus.
Correcting people, even when we are not perfect ourselves, IS the merciful thing to do. Among the Corporal and Spiritual Works of Mercy, brotherly correction encompasses admonishing the sinner, instructing the ignorant and counseling the doubtful. Many Protestant and even Catholic sources will emphasize the faith of the "good thief" on the cross, who admitted his sentence was just, but that Jesus was innocent, and simply asked Him to remember him when He entered His Kingdom (Luke 23:42). The man's faith was an important part of his salvation, but not the whole story, for faith without works is dead. Look just a few short verses earlier, when the criminal, well aware of his own sins, rebukes the other who taunts Jesus. It wasn't one of the more tangible corporal work of mercy. He couldn't feed, clothe or otherwise comfort his fellow criminal on the cross, but he reached out to him in those dying moments to try to save him. So no, the fact that we are sinners does not give us an excuse for keeping silent in the face of others' sins. People may become defensive, and if they know your sins, they may throw it right back in your face. Let them, for such a sentence is just. Fight their pride with humility, and even admit, "I deserve that. I'm a sinful person, too. I don't have a right to judge, but a duty to reach out in love."
God has a never ending supply of mercy that He just wants to pour out upon all of us, but He also gives us free will. He will not force His mercy upon us. He will not force anyone to be with Him for eternity. That would not be mercy, but indifference. We must confess our sins. We must repent. We must turn around. We must reach out to others to do the same, even when it's uncomfortable for them or for us. To fail to do so would be the most unloving, unmerciful thing we could do to our brothers and sisters.