We do not “fellowship” does not mean not associate, it means do not share in being a participant in darkness which is unfruitful. So we should reprove them (hard to do with no association) The fruit is seen in the things (which are not done in secret) nor could reproof come by “secret” (privately) but the fruit comes in the manifestation of light.
(Eph 5:11) And have no fellowship with the unfruitful works of darkness, but rather reprove them.
(Eph 5:12) For it is a shame even to speak of those things which are done of them in secret.
(Eph 5:13) But all things that are reproved are made manifest by the light: for whatsoever doth make manifest is light.
I’m told, “be ye not conformed to this world” am I’m not, I am transformed by the renewing of my mind (which comes from within God’s instructions in the Word and guidance from the HS) and which is an ongoing process and often in the face of tribulation, but that is the only way I can prove what is that good, and acceptable, and perfect will of God in a world of unbelievers.
Romans 12:2: And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.
Where is the spiritual courage? Will you not eat with the sinners, the unrighteous, in order to present the truth?
The Pharisees asked: Why does your Master eat with the publicans and sinners?
(Mat 9:11) And when the Pharisees saw it, they said unto his disciples, Why eateth your Master with publicans and sinners?
(Mat 9:12) But when Jesus heard that, he said unto them, They that be whole need not a physician, but they that are sick.
(Mat 9:13) But go ye and learn what that meaneth, I will have mercy, and not sacrifice: for I am not come to call the righteous, but sinners to repentance.