I don't think I have any answer but if this is of any encouragement I will share. My husband has a long time male friend that has been in the drug scene for many years. His mom we know well and she has been praying for his deliverance and salvation for a little over 25 yrs now with no change in sight. However this guy has been in motor type injuries and close to death situations E.R. many times but God has not allowed his life to be taken from the enemy due to constant prayers of his mom. She also has been shown his deliverance and salvation of his soul. I have noticed lately in his life the light of Gods truth slowly sinking in getting brighter but very slowly. God is doing a work and His Word does say he will finish what He has started. It just seems like some He works more slowly for the sake of the soul of the person. That when the seed is sprouted the fruit will be true genuine repentance and salvation. God knows what it will take to bring that wondering lamb back, even if it means breaking their leg as in the case of this friend of ours. As long as there is breath there is hope. The bible does say however to pray that the blinders be removed from their mind   because it is the enemy that blinds them from seeing.  There is also the scripture story Jesus told about the first shall be last and the last shall be first. With some souls it takes them to the ropes end of their life before they see and repent and they make it barely into the kingdom, but they make it. Keep on keeping on!!!! There are also prayer chains out there where lots of people pray for a specific person. That's all.