To be completely honest I have only spent a little time studying each and I would say more so on the Jehovah's witness side. I have family that are Jehovah's witness. As a believer I have had a heart for these two with the understanding that they are false teaching which do have some critical doctrine differences. Jehovah's witness do not hold the deity of Christ, dont really deem faith alone, and so forth and Mormons also have significant differences as well (In relation to the Baptist Faith). I always assumed that nobody could be truly saved through these false religions. I realize we arent ones to judge in that respect, but where do you think their Gospel's become insufficient to lead someone to Christ? In other words, what are the key essential pieces of the Gospel that must be understood in order to lead someone to Christ? You may want to include some beliefs on how and when the Spirit of God would and would not work, based on biblical understanding that God has revealed to us to be equiped to place our preaching in the path of grace.