John Calvin Commentary Genesis 5:1

"This is the book of the generations of Adam. In the day that God created man, in the likeness of God made he him;" — Genesis 5:1 (ASV)

This is the book of the generations of Adam. In this chapter, Moses briefly recounts the length of time that had intervened between the creation of the world and the deluge, and also slightly touches on some portion of the history of that period. And although we do not comprehend the design of the Spirit in leaving great and memorable events unrecorded, it is, nevertheless, our duty to reflect on many things that are passed over in silence.

I entirely disapprove of those speculations that everyone forms for themselves from mere conjectures; nor will I provide readers with the opportunity to indulge themselves in this regard. Yet, it may, to some degree, be gathered from a bare and seemingly dry narration what the state of those times was, as we will see in the appropriate places.

The book, according to the Hebrew phrase, is understood as a catalogue. The generations signify a continuous succession of a race, or a continuous progeny. Furthermore, the purpose for which this catalogue was made was to inform us that in the great, or rather, we might say, prodigious multitude of people, there was always a number, though small, who worshipped God; and that this number was wonderfully preserved by celestial guardianship, lest the name of God be entirely obliterated and the seed of the Church fail.

In the day that God created. He does not restrict these “generations” to the day of creation but only points out their commencement. At the same time, he distinguishes between our first parents and the rest of mankind, because God had brought them into life by a unique method, whereas others had sprung from a previous stock and had been born of parents. Moreover, Moses again repeats what he had previously stated: that Adam was formed according to the image of God, because the excellence and dignity of this favor could not be sufficiently celebrated.

It was already a great thing that the principal place among the creatures was given to humanity; but it is a nobility far more exalted that humanity should bear resemblance to its Creator, as a son does to his father. Indeed, it was not possible for God to act more generously toward humanity than by impressing His own glory upon it, thus making humanity, as it were, a living image of the Divine wisdom and justice.

This also has force in repelling the calumnies of the wicked, who would gladly transfer the blame for their wickedness to their Maker, had it not been expressly declared that humanity was formed by nature as a different being from what it has now become, through the fault of its own defection from God.