Some people think Mormonism is simply a branch of Christianity, such as Methodism or Lutheranism. Yet biblical Christianity actually has more in common with Islam than Mormonism - at least Islam is monotheistic (believes in one God).
Back in 2007, Dr. James White wrote, "For anyone who has studied the theology of the Church of Jesus Christ of Latter-day Saints, listening to talk radio of any kind during this political season is proving painful. Being even a conservative talk show host obviously does not impart to you even the slightest bit of theological or historical knowledge. The flood of utter ignorance of LDS beliefs that I have heard flying out of my radio speakers has been breathtaking. "Mormons are just a different kind of Christian" seems to be about as deep as most people want to go, and one thing is for sure: if you dare try to address the fundamental differences between Mormonism and Christianity, you will not be given the time of day. No one is interested. Now, I must admit, I have heard a few make the attempt who never should have, either. You need to know what you are talking about if you are going to try to make the case with clarity."
He continued, "It is to that end that I would like to provide you with some basic information regarding the LDS doctrine of God. My sources will be LDS. I am drawing from my book, Is the Mormon My Brother.... The current political campaign has opened up the opportunity for dialogue. The door is not wide open, but, if the Christian is prepared, knowledgable, and has a clear direction in mind, he or she has an opportunity to speak a word in due season, to God's glory."
A series of articles by Dr. White can be found here which are very useful for anyone wishing to dialog with people caught up in the extremely polytheistic religion of Mormonism - the Church of Jesus Christ of Latter Day Saints.