I had a relationship with a "fellow believer" for a long time as a member of the same church. We were close socially, playing golf together and lunch usually once a week and sang in the choir together. However he got involved with a cult primarily do to his spouses persuation. I confronted him about this and questioned his involvement and asked him if he believed that Jesus Christ was God. His answer was "NO I believe that God is God" Later I learned that they use only the Old Testament and had torn the New Testament from their Bible. He had been a member of the SBC church for 50+ years and had served the local church in numerous capacities. I severed my relationship with him by explaining I Jn 2:22/23 which he was familiar with. This was perhaps in the top 5 hardest things I have had to do in my life. Since then I have been second guessing my decision as most all of my fellow church members still are actively involved with him socially and he has now gone to a retirement center (nursing home).