Doesn't Genesis 1:26-27 teach that God has a body of flesh and bones since we are made in His image?
When the Scripture states that man was made in the image of God, we dare not add to that statement an idea from our own head and make it mean 'in the exact image.' To do so is to make man a replica of God, and that is to lose the unicity of God and end with no God at all. It is to break down the wall, infinitely high, that separates That-which-is-God from that which-is-not-God. To think of creature and Creator as alike in essential being is to rob God of most of His attributes and reduce Him to the status of a creature. It is, for instance, to rob Him of His infinitude: there cannot be two unlimited substances in the universe. It is to take away His sovereignty: there cannot be two absolutely free beings in the universe, for sooner or later two completely free wills must collide. These attributes, to mention no more, require that there be but one to whom they belong.
When we try to imagine what God is like we must of necessity use that-which-is-not-God as the raw material for our minds to work on; hence whatever we visualize God to be, He is not, for we have constructed our image out of that which He has made and what He has made is not God. If we insist upon trying to imagine Him, we end with an idol, made not with hands but with thoughts; and an idol of the mind is as offensive to God as an idol of the hand (A. W. Tozer, "God Incomprehensible" in The Knowledge of the Holy).
The primary question that needs to be asked in Genesis 1:26-27 is, "What kind of image is being taught in this passage?" Is it a physical image only, a physical and spiritual image, or simply a spiritual image? LDS look at themselves and assume it must be physical and spiritual. So for LDS, technically God is in man's image. That is, God generally resembles the way we are physically and spiritually, and thus He must have a body.
A Christian, though, is not so beholden to the way things appear. God can appear anyway He wants, but that doesn't mean that is what He is by nature. So it is important to note that an image or a resemblance is not a nature. These are two different things. A stick may appear bent when submersed in water, but here the senses yield to the mind that affirms the stick in its nature remains straight even when it is submersed. Similarly, we all know the Holy Ghost is not a dove even though He "descended in a bodily shape like" one (Luke 3:22).
So how do we know if God's nature is such that He in fact has a body or not? I submit we know this in various ways, but one obvious way is due to what the Scripture says about God's nature. If the Bible truly affirms that God is "invisible" and not simply "hidden" (cf. 2 Corinthians 4:3 and Colossians 1:15), if it affirms that God is an omnipresent spirit and not simply that His power is everywhere (John 4:21-24), and if the Bible affirms that God is too big for the heavens and the earth, let alone a body (1 Kings 8:27), then it should be clear that God's nature is such that He does not have a body. This should not be surprising, since God is not a man by nature; He is God by nature (Psalm 90:2, Hosea 11:9, and Galatians 4:8). That is, He has always been God contrary to Joseph Smith's claim.
Consequently, a Christian is warranted in holding that we are simply in the spiritual image of God, and certainly not in His nature. That is, since God is not physical by nature, we must image or resemble Him spiritually (e.g., we reason, love, and exercise free agency particularly in moral contexts). Similarly, a dog may image or resemble its master somewhat when the former acts in the way the latter does. But despite how good the pet may be in its imitation, none of us would assume dogs and humans are, or ever could be, of the same nature.
R. M. Sivulka