Dale, it's late here where I am (3:30am) and I need to get some sleep. I'll complete where I was tomorrow. We still have time.
As for her passion of faith. There are many people who are driven by faith and strictly religious who have strayed. We are human and fallible. Your wife is no different.
There is the possibility that she did not sleep with him, however the FACTS say she was truly in love with OM. That, if we go by biblical standards, constitutes adultery. The question of whether she did or did not can be answered later. First you need to get her complete commitment to working on the marriage. And that can only be confirmed by consistent actions.
In the meantime try get some rest. You will be getting conflicting advice here. I will share what I think you need to do (which I have not done yet) and others will tell you other things. God has given you a mind and an ability to discern. Use it.
The truth here is that we're only working on about 25% of the facts because people here only share about half of what has happened. The other 50% is your W's viewpoint. So we do the best we can with the information we have available.
I'm not against MC or Retroueville... but to get to those points you need complete "buy-in" from both parties or else they WILL fail.
M:11 | T:12 | Status: Married 4C's of WAS communication: Cool, Calm, Collected and CONFIDENT