What you are saying is that non-Christians that understand Christianity first hand tend to be more anti-Christian and a greater threat to the church than those who know little about it.a dangerous atheist is one who was once religious. They know the scripture better than most and certainly have an agenda ,
I can't argue with that.
You seem to be overlooking the significance of that. You're talking about an awful lot of bright, reflective, independent thinking, well educated, and morally upright people like many of the unbelievers posting in these threads. Are they all dangerous? Is there no merit to their opinions?