Nothing is more wrong and unbiblical than to publicly berate various sinners, and then say that you are a sinner too.
That’s called hypocrisy.
“He also shall be my salvation: for an hypocrite shall not come before him.” (Job 13:16).
“Wherefore laying aside all malice, and all guile, and hypocrisies, and envies, and all evil speakings,” (1 Peter 2:1).
Why is it unbiblical? Well, according to Scripture, Christians are not sinners.
“And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins” (Matthew 1:21).
“Unto you first God, having raised up his Son Jesus, sent him to bless you, in turning away every one of you from his iniquities.” (Acts 3:26).
Either Jesus is the Saviour or not, because, “But your iniquities have separated between you and your God, and your sins have hid his face from you, that he will not hear.” (Isaiah 59:2).
“Being then made free from sin, ye became the servants of righteousness.” (Romans 6:18).
“But now being made free from sin, and become servants to God, ye have your fruit unto holiness, and the end everlasting life.” (Romans 6:22).
If a person accepts the righteousness of God, and then wisely, lovingly and properly explains about the existence of God, His law with its awful consequences, true repentance and what Jesus has ALREADY DONE for us, then they are going to be able to best help others come to realise, by the spiritual awaking of their conscience, that their state is precarious.
“And he shall redeem Israel from all his iniquities.” (Psalm 130:8).