In response to this seeming contradiction, blogger and BYU evolutionist SteveP recently suggested that the words "first man" might refer to the first time a spirit child of God was placed in a physical human body. According to this view, no matter when humans first appeared on earth, it was only about six thousand years ago that "the spirit and the body [first became] the soul of man" (D&C 88:15)
The body is dead without the spirit
According to the Church's Guide to the Scriptures, "the physical body cannot live without the spirit." This statement is made in reference to the words of James that "the body without the spirit is dead" (James 2:26).
We teach investigators and new members that "without the spirit, the body has no life and is placed in a grave." (Gospel Fundamentals, 195; see also Preparing for Exaltation: Teacher's Manual, 34.)
We teach our young children that the body is lifeless without the spirit:
"Hold up your hand, and explain that it represents the spirit that is inside our bodies. The hand can move. Hold up the glove (stocking), and explain that it represents the physical body. When we are born, the spirit and the body are temporarily joined together, and the spirit gives the body life. The body cannot move by itself. But just like when the glove is placed on the hand, the body becomes alive and can move when the spirit enters it. (Put the glove on your hand.)" ("Primary 4: Book of Mormon, 160; see also 2007 Outline for Children's Sacrament Meeting Presentation.)
All humans are spirit children of God
So what about all those humans that supposedly lived before Adam? Again, BYU's SteveP postulates that humans before Adam might have been made alive by spirits that were not the spirit children of God. According to this view, humans descended from Adam are spirit children of God.
But the Church clearly teaches that "all" humans are spirit children of God. Here is the official statement:
"All human beings—male and female—are created in the image of God. Each is a beloved spirit son or daughter of heavenly parents." ("The Family: A Proclamation to the World.")
In a document of the magnitude of the family proclamation, the First Presidency and Twelve do not make casual, offhand declarations of doctrine. The family proclamation is of great significance to our generation and it means exactly what it says.
Conclusion
The scriptures teach that the body without the spirit is dead. The Church teaches that all humans are spirit children of God. The word of the Lord is that Adam was "the first man of all men" (Moses 1:34).
SteveP can believe whatever he wants about humans before Adam. Apparently, he can even teach those ideas at BYU. But his BYU students should be aware that some of his assertions contradict what is taught by the LDS Church.