The thought that one of the people exercising authority in your faith community and shaping lives may be unconverted should terrify us and comfort us because of the benefits to victims of demon-possession and medical illness.
And when he had called unto him his twelve disciples, he gave them power against unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease.
In Matthew 10:1 we learn that authority over demons, sickness and disease can be a phenomenon outside of Christian conviction.
At the end of Luke’s gospel Peter is still unconverted and it must be acknowledged that this is the case for all of them since conversion requires Christ to give the Holy Spirit so that one can become a child of God.
But I have prayed for thee, that thy faith fail not: and when thou art converted, strengthen thy brethren.
Luke 22:32
One does not even need to be in the group of Christ followers. The case of the strange exorcist illustrates this.
And John answered him, saying, Master,we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us. But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me.
Mark 9:38-39
We can expect unconverted people to be a part of this phenomenon in the 2nd millennium after Pentecost. Sobering and highly and disturbing.