>>> God judges the morality of those outside the Church! <<<
The message from Apostle Paul is that we are to judge those people within the Church. Separate yourselves from sinners is the message of the Bible. Judge those who call themselves brothers and sisters. Don’t worry about those outside the church, because God judges those outside. Paul writes that you would have to leave the planet if you were to judge all the sinners outside of the church.
Jesus provides a simple process. Confront the sinner first in private. If no repentance occurs, then confront him or her with one or two witnesses. If there is still no repentance, tell it to the church [go public]. Christ says to shun and excommunicate the sinner within the Church who will not repent.
“Moreover if your brother sins against you, go and tell him his fault between you and him alone. If he hears you, you have gained your brother. But if he will not hear, take with you one or two more, that ‘by the mouth of two or three witnesses every word may be established.’ And if he refuses to hear them, tell it to the church. But if he refuses even to hear the church, let him be to you [and the entire Church] like a heathen and a tax collector.” Matthew 18:15-17
Why should we bother doing this? It gets back to the fruit basket. You will know them [true believers] by their fruits. Therefore, bear fruits worthy of repentance [Matthew 3:8]. How do you know you are keeping company with good or evil people? Examine their fruit. In this case, you examine the behavior of “anyone named a brother [or sister].” Take heed!