I think your question goes much deeper that it first appears, so please bear with me as this is going to be long...
"So God created man in his own image, in the image of God he created him; male and female he created them."
This is quite an amazing statement -- God's image isn't just a singular person, but multiple and includes built-in relationship. That dynamic is love itself and was meant to exist between man/woman and between humans/God. This is the way things were created to be. This is what marriages are meant to reflect. This is at the core of what Christianity teaches and points toward.
But humans chose to abandon love and to pursue self-centeredness. In fact, they betrayed God and tried to take his place. This broke the relationship between God and humans and the consequences led to a very broken world. Many of the failures and repeated breaks in relationship were captured over and over in the Old Testament as things spiraled downward. This is the world we live in today -- broken.
Jesus came to make a path for reconciliation between a rebellious humankind and a loving God. He forcefully confronted the religious leaders and the rules they had setup which were burdensome and missed the entire point -- which was "'Love the Lord your God with all your heart and with all your soul and with all your mind.’ This is the first and greatest commandment. And the second is like it: ‘Love your neighbor as yourself.’" Jesus came to help restore the broken relationship between humans and God by pointing to love as the key and by paying the penalty of our betrayal.
Christianity, very simply, is the good news that God wants to forgive/reconcile and has provided a way for it to happen. What is asked of us is that we own up to our rebellion, turn away from our self-centered ways, be humble, accept His love and love him in return. It is a gift. It is about relationship. It is about love. This is absolutely central to Christianity.
Can a person be a true Christian and cheat?...I’m trying to determine if my wh is saved, or ever was saved at all or if it was just all a big farce.
Unfortunately, there is a lot that isn't central to (or even part of) Christianity that can end up getting in the way and making things more difficult than they need to be. This is why I believe your question doesn't have a quick answer. Just like some of the religious groups during Jesus' time, people today have attempted to layer on additional thoughts/rules/interpretations to scripture and there is disagreement between groups on various rituals, doctrines, etc. "True Christian" and "is saved" are a couple of terms that are more connected to the layers that people have put into religion. Some believe that once a person is saved, they are always saved -- that is what gives rise to the whole thought of whether a person was a "true Christian" or was ever saved in the first place after some sin has been exposed. There are many other beliefs around how being saved works and the arguments around these things have gone on for centuries. IMO, these things all too often become a tangential discussion that ends up missing the main point altogether. I think that what you asked is somewhat of a loaded question due to all of this, so I think it is important to go back to the very beginning of things to get the answer. (ETA -- I don't mean any disrespect if you hold to a particular doctrine or belief on salvation and I certainly don't want to turn this conversation into a discussion of religion itself)
I think it all comes down to love and relationship. An affair is a break of love and relationship, so being involved in one is a betrayal of both God and a spouse. It is an outward indication that self-centeredness has taken root and that love isn't being practiced. It is a heart issue.
After Dday, some WS's will end up seeing how they abandoned real love to chase after something that was counterfeit and then decide to be humble, admit their failure, work hard to change and ask for help/support. Others, to some extent or another, won't and that will become apparent down the road. One can work at love or one can try to fake it while being self-centered. I've seen actions in others who profess to be Christians that indicate both paths. Some have failed and this becomes an event where they recognize their need to change. Some have all the external appearances of being a Christian, but have a hidden side and refuse to face their lack of real love even after experiencing a Dday. It is very, very difficult to really know where someone stands with God until you are close to them and even then it can be difficult to see where their heart really stands. (ETA -- unfortunately, with my W having been a serial cheater and since many of the APs were "Christians", I've seen more than I care to on how the aftermath can play out)
I'll speak for myself and my wife as an example. Both my W and I were raised in the Christian religion and came to call ourselves Christians at a young age. In the eyes of others, everything looked fine on the outside even after there were multiple Ddays (we kept them well hidden). However, both of us would say that the last Dday was a pivotal moment in our faith. It took that last Dday for my wife to realize that she was out of control, that she was manipulating others in an attempt to get a feeling of validation for herself, to see that her underlying needs for validation came from her FOO (family of origin) and that she was trying to get love from men instead of God. It took that last Dday for me to recognize the codependency within me -- the thought that sacrificing for others was "Christian" when, in fact, it was an attempt to pursue getting the love I wanted from others (all stemming back to my own FOO) while it displaced God. The last Dday awoke both of us to the dysfunctional paths we were on and has led to deep changes in both of us. While we may have appeared to be Christian on the outside and we both would have claimed to be Christians, in hindsight, we both were missing the mark.
Based on my own perspective and experience, I don't think that the emphasis belongs on whether your WH was/is saved, but on whether he is being "saved". In fact, I'd prefer to use another term (e.g. reconciled) because all too often "saved" can focus on self-centered things like obtaining eternal life, living in a heavenly mansion, etc., instead of on the restoration of love/relationship. Regardless, right now you know that your WH's relationship with God and with you is broken due to the A, so he is at a point where God's invitation to reconciliation is very relevant. The question is whether your WH sees that, is troubled by what he has done, owns it and takes the necessary steps to reconcile/love.
[This message edited by Crushed7 at 10:31 PM, June 24th (Sunday)]