As mentioned earlier, Jehovah’s Witnesses are growing at an alarming rate and the worst part of that is the majority of it’s growth are former mainline church people. They present their beliefs in a very appealing, dedicated, and impressive way. To any person who is disgruntled with the "church" because of a bad experience in a church or with a person in a church, these people seem to have the answer. We must always remember that Satan will appear as an Angel of Light (2 Corinthians 11:14), and he knows what’s going on in your life and will send his messengers to you door (Jehovah’s Witnesses) at seemingly just the right time. He seeks out those who are vulnerable and presents his deceptions to lure you into the trap (1 Peter 5:8).
Another important reason is that someone in your family or a friend may fall prey to this group. It will become of great importance if this happens, to reach them before they cut off relations with you.
I know a couple that raised their family in a Christian home and went to a good sound church all their life. One of the sons in his 30's at the time got involved with the JW's and now have moved away from his family and does not even speak to them. This is what can and will happen if they lure one of your family members or friends into their belief. To this day that son still will not speak to his parents and it is extremely painful to them.
There are some excellent materials available for educating yourself on how to talk to these people. David A. Reed has three great books, "Jehovah’s Witnesses Answered Verse By Verse", "Index Of Watchtower Errors", and "How to Rescue Your Loved One From the Watchtower". Ron Rhodes also has a book called "Reasoning From The Scriptures With The Jehovah’s Witnesses", which I very highly recommend. It is one of the most complete books I’ve seen on preparing one for talking to a Jehovah’s Witness. Although these books are excellent materials to have and I highly recommend all the books mentioned, my approach is somewhat different. I pray the Lord will use these materials and all of the others as effective tools to free these people from the bondage of deception.
The primary focus of this material is to work only out of the New World Translation by making a chain reference of various scriptures to reveal contradictions according to their beliefs and what scriptures indicate. There are starting points to use and follow a chain of scriptures relating to the same topic. If you make your markings with red ink and highlight the scriptures in view, it will help speed the process. You can make notes on each page if needed on edges, top, or bottom to keep your train of thought. If you take time to study each point, then you can get by with a small amount of notes on the pages and you will know the questions you want to ask at each key point. Keep in mind that the principle is to reveal contradictions and enforce Jesus’ Deity. My prayer is that the next time they come knocking at your door, you can invite them in and go over these points with them. If they come to your door and you are not able to talk at that time or are not prepared, simply ask them to come back. If you tell them you would like to talk to them but just can’t right now, they will come back. This will also give you a chance to get your thoughts together and most importantly of all pray. May GOD bless your efforts and the use of this material.
Almost all of this material deals with Jesus and his Deity because in my opinion, this is the biggest separation between Jehovah’s Witnesses and Christianity. Since Jesus is the only way (John 14:6, Acts 4:12), and He said "If I be lifted up I will draw all men to me", I believe this is the most important issue. All Scriptures will be from the New World Translation for your benefit, this way even if you do not have a copy you will know how it reads. It is best to ask them to read along with you, but you should do the reading so you can stress the points.