-A8
"You should reread your history and look for objective sources outside your church."
Why is that an ad hominem? Because it is about the person rather than the issue being discussed. In particular, it is saying, "You are ignorant; you need to go learn." That's an ad hominem. To avoid the ad hominem, instead of speaking about one's interlocutor, speak about the issue. So, for example, say, "That's not true; these sources show that what you said is false."
-A8