As far as the rank and file members I would just point out to them the errors of their ways, open their minds and hearts and then show them the faults of the organization they were following. If by the end they were ashamed of ever being a part of them then I would forgive them because most of them don't have the ability to discern when they are being lied to and are good people at heart. They are just misled and being a sinful imperfect person that is to be understood. But if after showing them the atrocities of the organization with their hearts and minds being opened and they still cling to it then I would inform them that they will share in her fate. Flee from the disgusting thing that you do not share in its fate. They will have their chance to flee but not all will take advantage of it. They will go down with the worst of them but not for a lack of serious Godly convincing.