Most likely there is nothing to be done as they have not evolved to the point of accepting the truth about Satan yet. It is not possible to brute-force understanding to someone who is not ready. At best, you can influence them in minor ways or do spiritual warfare rituals on them in hopes of speeding the process of their evolution (if possible, as they might also be going in another direction).
You should also be mindful of how you use your time and energy. Do you prioritize your own advancement and doing spiritual warfare in general terms (which has an indirect positive influence on your friends as well), or do you prioritize someone else not even knowing if the end result is favorable? Something in-between? Again, be mindful of how you use your time and energy.