When I was meeting with Mormon missionaries, it was their view of God that was particularly grieving to me. I wanted them to know the God who is, was, and always would be God, who is not of the same species we are, who isn't limited by a physical body, and who was always perfect, never sinned, and isn't getting better (because such a thing wouldn't be possible).
But in this video by Aaron Shafovaloff, some Mormons explain why the very same LDS ideas about God that horrify me are actually encouraging to them. How can this be? The answer goes to the heart of the difference between the Mormon and Christian gospels.
For those of us whose main, ultimate purpose is to glorify God and enjoy Him forever—a goal which can only be achieved by throwing ourselves into His mercy and grace because of our lowly sinfulness, we rejoice in a perfect and holy non-human God to trust in and worship. But for those Mormons whose main purpose is to progress to godhood through a series of requirements, this kind of God is the ultimate discouragement.
They are horrified by the thought that God is, and always has been, a completely different kind of being from us in form, eternality, holiness, and perfection because that puts the possibility of our becoming like Him (their primary goal) completely out of reach. But if we are of the same species as God, if He were once a sinner just like us, then they know that godhood is attainable, so they're encouraged to not give up their striving. As one person in the video puts it, "That's really what the [LDS] teachings are—just try to be better the next day than you were the day before."
So while Christians are trusting only in God to cross the unimaginable distance between us by paying for our sins, Mormons are working to pay God back what they owe Him (as this LDS parable explains). You can see how an understanding of the vast difference between God and human beings will either cause us to rejoice or despair, depending on our goal.
If you're interested in understanding the theological differences between LDS and Christian beliefs more clearly, James White's book, Letters to a Mormon Elder, can be read for free online. Here, also, is a list of Bible verses from CARM that can help you pinpoint where we differ (HT: Apologetics315).