However, it also provides instructions on what to do if you find a Christian brother in sin. Remember, sin is a personal matter between the sinner and God. It requires confession, repentance and a turning away from the sin. The Bible says: "Brothers, if anyone is caught in any transgression, you who are spiritual should restore him in a spirit of gentleness. Keep watch on yourself, lest you too be tempted." [Galatians 6:1-2] Sin is also not a matter to be brought up in public unless it is persistent and there is no sign of repentance or turning: "As for those who persist in sin, rebuke them in the presence of all, so that the rest may stand in fear." [1 Timothy 5:20]
Indeed, Jesus forgave the woman at the well caught in adultery: "Jesus bent down and wrote with his finger on the ground. And as they continued to ask him, he stood up and said to them, “Let him who is without sin among you be the first to throw a stone at her.” And once more he bent down and wrote on the ground. But when they heard it, they went away one by one, beginning with the older ones, and Jesus was left alone with the woman standing before him. Jesus stood up and said to her, “Woman, where are they? Has no one condemned you?” She said, “No one, Lord.” And Jesus said, “Neither do I condemn you; go, and from now on sin no more.” John 7:6-11
Covering the sin or nakedness of a brother is found not only in the New Testament but also in the Old:
"The sons of Noah who went forth from the ark were Shem, Ham, and Japheth. (Ham was the father of Canaan.) These three were the sons of Noah, and from these the people of the whole earth were dispersed. Noah began to be a man of the soil, and he planted a vineyard. He drank of the wine and became drunk and lay uncovered in his tent. And Ham, the father of Canaan, saw the nakedness of his father and told his two brothers outside. Then Shem and Japheth took a garment, laid it on both their shoulders, and walked backward and covered the nakedness of their father. Their faces were turned backward, and they did not see their father's nakedness. When Noah awoke from his wine and knew what his youngest son had done to him, he said, “Cursed be Canaan; a servant of servants shall he be to his brothers.” He also said, “Blessed be the Lord, the God of Shem; and let Canaan be his servant. May God enlarge Japheth, and let him dwell in the tents of Shem, and let Canaan be his servant.” [Genesis 9:18-27]
Coming back to the New Testament, in Matthew 7 Jesus said: "Judge not, that you be not judged. For with the judgment you pronounce you will be judged, and with the measure you use it will be measured to you. Why do you see the speck that is in your brother's eye, but do not notice the log that is in your own eye? Or how can you say to your brother, ‘Let me take the speck out of your eye,’ when there is the log in your own eye? You hypocrite, first take the log out of your own eye, and then you will see clearly to take the speck out of your brother's eye." [Matthew 7:1-5] This is a stern warning against Hypocrisy which Jesus repeatedly called out in the people around Him. As we know, we are all sinners saved by the Grace of God. "...for all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. This was to show God's righteousness, because in his divine forbearance he had passed over former sins. It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus." Romans 3:23-26. Remember, it is very easy to call out a brother's sin, but in doing so, are you being a hypocrite? Have you examined your own life first and made sure there is absolutely no sin in it? If there is even the slightest sin in your life, you are being a hypocrite, and it is not your place to judge a Christian brother. Leave the judging to God, and the sinner's conscience to confess, repent and turn from their sin. It is not yours to tangle with.