There does come a time when we should cease fellowship.

Often as leaders, we must discern if a person is a tare or a wolf.
The items and issues below help us discern. I have seen where leaders seeking to “restore” ministries will bring men in that have a history of unspeakable things, thinking if they can minister they will improve their living. Lives given to sin often speak to spirits that are operating in that person’s life and the outflow of that will not fix anyone. Let’s not think we are more merciful, wise or insightful than Jesus or the Apostles. Of course, some people make the mistake and do the opposite of what the scripture says below and put them in leadership or use them to preach Revivals.
Fornicators, greedy, Idolators, Abusive/Profane, Drunkards and Dishonest Cheat

1 Corinthians 5:11
But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolator, or a railer, or a drunkard, or an extortioner; with such an one no not to eat.

Of course, today they might be invited to preach Revivals.

We are more merciful and wise than Paul.

Jesus made an exception.

Those who refuse to hear the wisdom of leaders and the church.

Matthew 18:17 And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican.

Those who traffic in false doctrine

Romans 16:17 Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them.

Those who refuse to obey the Epistles as scripure.

2 Thessalonians 3:14. And if any man obey not our word by this epistle, note that man, and have no company with him, that he may be ashamed.

Those who teach the doctrine Prosperity Gospel

1 Timothy 6:5. Perverse disputings of men of corrupt minds, and destitute of the truth, supposing that gain is godliness: from such withdraw thyself.

Those who preach, believe and teach a doctrine that is not true.

2 John 1:10 If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed:

Mercy and Grace are always in order, however, there are times when we must be willing to protect the flock from wolves who will defile the sheep.