@
Davy
From what I have studied in the Bible, this issue can be rounded into one specific point.
Your post deals with a member of a congregation which would be a relatively small(hopefully) percentage of people
we are forced to deal with or who we love or is someone who is effecting someone we care for.
Spouses,children,parents,in laws,authorities,co-workers,bosses and the list goes on.
In other words those already on the outside who we love or have a position to inflick the evil on us or someone we love.
I know we are not supposed to be unequally yoked but sometimes two unbelievers marry and down the road one receives Christ
which can cause tension.Since God hates divorce and to remarry is adultery according to Jesus then an understanding of how to intercede on a spouses behalf might be needed unless you want to spend the rest of your life alone
Or maybe you have a good job in a hard to get into field and your boss brags about his evil exploits.
The effectual fervent prayer of a righteous man availeth much and nothing is impossible with God.
I was granted the gift of repentance by God from the prayers(and the power and joy I saw in my believing spouse) of a small group of fervent Christians(including my wife) who
prayed for me for four years before God opened my eyes and revealed to me the darkness of my path of unbelief.
I was not what the church would consider evil,I just wanted nothing to do with them.
I have seen God grant the gift of repentance to some hard cases.
I was a hard case because I didn't have any of those "in your face" or easy to spot sins" that
gave me the impression that I didn't even need Jesus.
My wife became a believer after we were married and I was impressed by her peace and joy so I certainly tested
her to see if her God was real.Turns out he is and he is able to save to the uttermost.
Separating yourself from the evil is a physical thing and should not affect your intersession to God on that persons behalf.
If separation is not feasible then you must become an expert on overcoming evil with good.
We just need to study,pray and practice the art of spotting the baby in the bathwater before both go down the drain.