I was in the same position as your wife, I didn't stop beleiving in God, but I was influenced by others and I stopped believing in the theology and doctrines that were uniquely LDS, but in God, I still believed, I still had faith in Jesus Christ as my saviour, I joined and left several different churches over the years,I was searching, I eventually I returned to the Church. I now have a strong testimony,Stronger than I had ever had before I left the church, I spent all that time trying to find what i'd lost somewhere else, then rediscovered it where I first had it, sometimes we don't realise what we have until we loose it. Sometimes you have to walk down the wrong path and experience the dead end for yourself to then realise that the path you were previously travelling on was the right one. That is not denying the Holy Ghost, To be in that catagory, you would knowingly walk down the dead end, telling others to do likewise, whilst knowing you were leading them to a dead end.This is what Satan does.