He's blindsided by the fact the JWs helped him get off drugs and brought stability to his life, and he's grateful to them because that's how he met me.
That is nice and something he can be grateful for. Over time though you can introduce him to experiences from other religions that have taken people from drugs, cleaned up their lives, provided them with family. There are plenty on the net. I found it very revealing that JWs were just like so many other religions in that regard, and it really opened me up to realising the fallacy of there being one true religion.