Don't be Put Off Guard by Hostility or Antagonism
Many cultists will become hostile or irritated against anyone who dares to question or oppose their beliefs. Some, like the Jehovah's Witnesses or Mormons will even try to trap you and make you lose your serenity. [The writer is sorry to say that in the early days they have succeeded in this with him several times because he was unprepared!].
Therefore, it is crucial that you always operate with 'the mind of Christ' (1 Cor. 2:16) that you behave as a Christian, and not ruled with your emotions. When you cease to operate with a Spirit-guided mind, you will inevitably begin to operate with fleshly emotionalism that will result in heated arguments, belligerence or even name-calling! Also, most importantly, don't refer to their leaders as 'false prophets' or as 'the Anti-christ', even if you are sure that they are! If you tend to get 'overheated' have the grace to apologize. Remember what Paul said, "Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer everyone (Col. 4:6).
If You Don't Win Them - Then at Least Warn Them
If you don't succeed in convincing them of their error, then you MUST in love warn them of the judgement of God upon their error and upon all perversions of His Gospel. Remember how Paul said, "Him we proclaim, WARNING every man, and teaching in all wisdom, that we may present every man mature in Christ" (Colossians 1:28). Read also Ezekiel 33:8 and Titus 3:10. Paul also warned those who were preaching 'another gospel', "But even if we, or an angel from heaven, should preach to you a gospel contrary to that we preached to you, let him be accursed! (Galatians1:8).
After They Leave, Evaluate the Encounter
Just as soon as they leave, evaluate for a few moments on the encounter. Jot down a few notes, in particular any areas where you were weak in explaining or defending the faith. It is especially important that you allow these encounters to become personal learning and strengthening experiences. You should write down any questions that you were confronted with that stumped you or confused you. Then do some research and get answers for these questions. If you fail to do this, you might eventually lose your confidence about having further encounters with cult members, and Satan the Devil will have won another victory!
After They Leave, Evaluate the Encounter
Just as soon as they leave, evaluate for a few moments on the encounter. Jot down a few notes, in particular any areas where you were weak in explaining or defending the faith. It is especially important that you allow these encounters to become personal learning and strengthening experiences. You should write down any questions that you were confronted with that stumped you or confused you. Then do some research and get answers for these questions. If you fail to do this, you might eventually lose your confidence about having further encounters with cult members, and Satan the Devil will have won another victory!
Follow-Up
(a) Put them on your prayer list, and specifically pray for them just as you would for any other person that you have had the opportunity to share Christ with.
(b) Take the initiative to follow them up in as many ways as you can. Don't just sit at home and wonder when or if they might call again. (Note: They took the initiative in the first encounter, so you can take it for the follow-up!).
This follow-up can take the form of a telephone conversation to again thank them for their visit, and at the same time, to re-issue an invitation for further discussions. You can send them some additional Christian literature that will continue to challenge their beliefs, as well as witness to them.
If they stumped you with questions you could not answer, be sure to do your homework by finding reasonable answers and sending them to them. This will accomplish two things. Firstly, it will let them know that you believe in your faith and care enough to go to the trouble of finding and getting an answer to them. Secondly, it will alleviate any delusions they might have taken home with them about thinking they successfully refuted Christianity.
