For some reason, when reading this passage I had the song "Things can only get better" in my head. Genesis 5 is an odd passage. I once knew someone I was working with comment on the ages in Genesis 5 as "missing the decimal point". I find the ages hard to square with what we know about human history, and it is not unusual for other Ancient Near Eastern texts to speak of such long lives. But all arguments aside (this is a devotional blog), what are we supposed to learn from this?
Firstly, the author re-iterates in verses 1-2 that humans are not merely an evolutionary accident, but created in the image of God - all human beings. In a manner typical of the era, the names of the fathers are mentioned. Seth is the image and likeness of his father just as Adam (and Eve) are the image and likeness of God. The message is, it still passes down, even if marred by Adam and Eve's actions. All people bear this stamp, and it runs down Adam's line.
It is also obvious that the greater the distance from the garden in time, the more the loss of access to the tree of life is manifest. Regardless of what you think about the factual nature of the ages, it shows the growth of corruption and decay that is discussed elsewhere in this passage, be it Lamech's attitude to violence, Babel or the comments made before the flood. Things don't look like they are getting better.
Today we seem to do violence more efficiently, it is still pervasive in society (Hollywood bears some of the blame) and we've seen enough shocking events - from the Holocaust to firebombing Dresden and Tokyo, Agent Orange, death camps, gulags and drones (to name but a few) to show that progress isn't always (often) moral. This might overlook many positive benefits which I don't want to downplay, but we need to recognise genuine evil when we see it.
So where is the progress in this passage? Like all of the biblical genealogies, it's at the end with Noah. He would bring rest from toiling with the cursed ground (for those in an agricultural society, this would have spoken very loud, for us in cities it is much more muted - but wait for climate change to ramp up further). Noah's story follows soon.
But this makes me think about other genealogies, like that in Luke 3 that follows Jesus back to Adam. Jesus is the image of the invisible God (Colossians) who fulfills all that image is meant to be. In doing so, in him, things can only get better.