1 John 5:16 If any man see his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.
17 All unrighteousness is sin: and there is a sin not unto death.
John teaches that all unrighteousness is sin, but he differentiates among sins.
There is a sin unto death and a sin not unto death.
If we find a member of the church in a sin unto death, we should not pray for the sin to be repented of ... because it can't be repented of.
If we find a member committing a sin which is not unto death, we should ask God and God will give him life for those who sin not unto death.
In order to carry out this instruction, we must make this discrimination.
Which means that we have a right and duty to judge a brother in order to decide whether we should pray for his repentance and restoration, or decide not to pray for him but leave him to the judgment of God.
The terminally sinful, for whom Scripture says we should no longer pray, are men and women who have known the truth but have now turned from it, they have known the law of God and will not now submit to it and who have heard the call to love one another as Jesus loved us but now refuse. In these things it would appear that they have crossed the line and belong to that dreadful category captured in the words of Hebrews six, ‘it is impossible to renew them.’