Blessings, Paul, and our prayers will continue to be that He would "take a coal from His altar and touch it to your lips," that you might boldly "speak His Word, and His Word only".
I have had some wonderful blessings in such discussions. And as regulars here can testify, I have also fallen short and let anger take over.
Take your Bible with you, of course, and have it indexed or marked; the better you know the Scripture, the better you will be able to give an account for your faith. But, as you seem to already well-understand, the most important thing is to be led by Him, and stay in prayer.
I think as well that it is very important to understand proper authority in such a situation (as has been on my mind today.
) We are warned to "touch not Mine anointed" -- but that warning is admittedly a bit ambiguous. I try to proceed with caution in the presence of such warnings, and avoid wherever possible even the appearance of
public confrontation with pastors, priests, rabbis, or prelates which might tend to undermine them in the presence of those who presumably are SUBMITTED to their authority.
But you yourself are given much authority in Christ Yeshua, which does not require earthly ordination, or Caesar's license -- to "tread on serpents and scorpions", "cast out demons", and even to cast down inappropriate vows of your daughters or wives -- if you do so in accord with His Word.
Do not attempt to sow discord among the sheep of another, or usurp authority not given by Him. But be equally careful not to yield what God has delegated to you, as head of your house, to anyone else. There is "a time to keep silence, and a time to speak", but leave the results up to Him. If -- after having spoken His Truth boldly -- they still do not have "ears to hear", you know you can wipe the dust off of your feet and "come out of her".
May God guide you and bless you,
Mark