These two verses in the genealogy of Adam might seem unimportant at first. It is the first place in the Bible that the created man is named "Adam." He has before been referred to as Adam, but here he is named Adam.
We need to ask, "Is this really Adam's genealogy?" Well, the answer to that is, yes and no, because the implication of verses 1-2 is that God is naming Adam. As his creator and thus father, He has taken His prerogative and named the man He had created in His likeness "Adam."
With God at the head—not Adam—this means this genealogy is God's, which includes Adam, and makes God the father of all humanity.
This genealogy eventually comes to Noah, who had three sons, and each of them married. After the Flood, all of mankind has sprung from Noah. But Noah came from Adam's line—or better, from God's line. Therefore, God is the Father of all of humanity!
Why is this important? It reveals that mankind has sprung from God. Because of this fact, man is substantially distinct from all other mortal creatures.
John W. Ritenbaugh
Other Forerunner Commentary entries containing Genesis 5:1: