There is only one thing to say:
 
James 4:11,12
 
Speak not evil one of another, brethren.  He that speaketh evil of his brother, and judgeth his brother, speaketh evil of the law, and judgeth the law; but if thou judge the law, thou art not a doer of the law but a judge,  There is one lawgiver, who is able to save and to destroy.  Who art thou that judges another?
 
Then there is the scripture that says "judge not lest you be judged" and "who are you to judge another mans (God's) servant."
 
Why are we taking someone who has personally given his life to see the salvation of souls for Christ, and now you want to attribute it to the work of Satan?  The pharasies of Christ's day did that when they attributed the works of Christ being done through the power of satan.  Christs reply was that you could say what you will about him, but to blaspheme the Holy Spirit would result in their not being forgiven during the present age nor in the age to come.  Does anyone out there want to join that group?