BootStrap....I don't personally know any christian who would say one should stay in a destructive marriage (even though there could be some) but I think what is called upon is the hope that one would hold in their heart for their marriage vow.
One could live away from their spouse if the need arises but still keep hope alive in their heart through prayer and fasting.
The journal was for the individual to examine their own life deeply to see if there was anything that was contributing to the failure of the marriage. None of us can change the other person....only ourselves. When a person suffers enough and falls so hard will they look up and seek God for the answers...(or not). God will help those who wish to change....for our lack of change (for the better) is actually a form of unbelief (faith) in the One who created us.