I think the biggest harm that even well meaning, moderate apologists, especially those in leadership positions do in this world is...
1 - Present that God will provide all the answers, and often feel confident that they can help through the Holy Spirit's guidance.
2 - Because of this, a follower or help seeker may turn away from far more trained and expert help that is unbiased.
3 - When the god follower fails to provide useful help, the effort to help turns to efforts to make excuses for God.
4 - Since God can't accept any blame or responsibility for anything in Christianity, the now hurting person is stuck, not only hurting, not only having avoided help that might have been more qualified, but now being viewed with suspicion because God chose not to answer that prayer.
Families that let their kids die, rather than take them to a doctor, were probably looked at as fantastic members of whatever church they went to... but then after trusting god failed to produce results, most of their fellow Christians will look at them as "not really a believer" and "they had free will and ignored god's answer to their prayer in the form of a hospital".
Going for divorce counseling at a church instead of with a trained marriage therapist? When the help fails... and it does at a greater rate than for non-believers... fellow Christians will blame it on the free will of one or the other partner, completely depending on who they were already friends with, or who they listened to. (if God really was guiding people, wouldn't he let them all know which side to take?)
Someone is having a rough time with drugs or suicidal thoughts, and go to the church or religious group for help.
If it helps, then God gets all the credit, but, if it doesn't... the person is blamed. Maybe they're not getting the help they need, or maybe the help they're getting at the church isn't well trained in what to do... but if that person fails, it'll be blamed on their free will, and not the church or god...
Keep in mind, at the beginning of all these events, the church leader will be convinced that he or she (usually he since women are second class in churches), is guided by the spirit.
This delusion not only prevents people from getting the help they really need, but then blames them when the second rate help they got from the church fails.
Instead of just suffering, now you're suffering with guilt heaped on top of it.
It's like if Christian's ran an Ambulence service, but showed up late to every emergency, then blamed the person who dies for not having better health or for not holding out longer until they got there.