My biggest weapon against the false teachers is the word of God and knowing it. I have looked at a dozen false church websites of various kinds and see all kinds of problematic statements. Some issues are secondary and a good apologist must know the scriptures well. A church claimed the sign gifts and while I do not agree with this, it's a secondary issue. Another church proclaimed that everyone is a child of God and hell and repentance are not necessary for Christ was just a good teacher. That's hell bound heresy! The false teachers will not buy a book I recommend but they will read the scriptures that I cite in letters. When I call up the dozen churches I have sent letters and chat with the false pastors I will go right to Gods Holy Word!! Know your Bible people! Heb 4:12, Psa 19, Jer 23:29, 2 Tim 3:16-17.