Many Christians who have had to deal with a jw on any kind of regular basis will come around to discussions on how salvation is accepted. Now the jw will say that salvation is through faith alone, but then they will insist that we must obey. Furthermore they have a great deal of faith in their spiritual regimen to keep them on the straight and narrow.
This is how I explained it to one recently.
So often when we are trying to understand God's relationship with man, it is useful to consider the analogy of a father to his child. Initially man was like an infant. He was completely unequipped in his experience and understanding to deal with the ability to know good and evil. Just like an infant that does not even know not to crawl off the bed, early man had no concept of the ramifications of sin. God had to deal directly with man to correct his behavior.
Later as man gained more knowledge and understanding, God gave basic rules. Do not kill. Do not steal. Do not worship other gods. Also once our children are able to understand our words, we give them simple commands. Don't play in the street. Don't run with scissors. Don't hit your sister.
Eventually though, as a parent you hope that while following the rules, a basic understanding of the rationale behind the rules will set in. Eventually you expect your child to grow to the point where they really don't need your rules to function. They have the maturity and judgement to make the right decisions. Now they will make mistakes, and you will have to correct them from time to time, but when it comes time to leave home, they have the sense they need to make it.
Now I also knew someone who was very strict with their child. THey gave him many rules. He followed them all. But he never grew in understanding of what the rules meant. When he left home and the rules of his parents he simply could not function at all.
That is what I think God is expecting from us in having the law now written in our hearts. We are no longer under the law of God's (or the jw's) basic rules. He is expecting us to show some doggone maturity and to know right and wrong without having a list of rules to follow. There are two basic rules. Any question beyond that is a matter of what is in your heart. If you are turning away from sin in your desires YOU ARE NOT SINNING!!!
My 2 cents. The jw didn't have much to say to all that.
THoughts?