well if I really loved my wife and definetly did not want a divorce like you said I would probably just lie to them and say that you have some doubts but you're sure you can work through them it's just going to take time or whatever. Then just fade away, your wife won't divorce you for being "spiritually weak" but "The Big D" (*trademark Watchtower bible and tract society*) might cause a divorce.
If it were me that's what I would do just say "Yeah this is the perfect orginization blah blah blah", you can mention that you're having trouble understanding a few things, then mention what they are. Be careful to phrase them as a question, then they'll think it's really something you're struggling with. Then you can just say, "it's going to take some time for me to work through this, so I apologize to my wife for having to deal with this, but it's just the way things are going to have to be for now."
That's just me, I'm the type that likes to just avoid conflict, hence why I faded away.