Learning to love my children as they chose to leave the church and seeing that they were/are good people had a lot to do with my leaving the church. Interacting with good people outside of the church was an important part of this as well when we were involved in a home school group with good people of many different persuasions.
It was a painful process, however. One that took several years to endure. My wife reminds me of it when I worry about my TBM kids not dealing well with our choice to leave the church. It is a process they need to go through too in order to see good people in different context.
How much of that fear stems from missionaries being thrust into all sorts of situations where they see some really nasty stuff, but don get to know very many of the "good" people who are out there because the good ones aren't terribly interested in the church? It's a self-selecting sample, and it skews their frame of reference of the world.