Interesting Patterns in Genesis

I have been enjoying opportunities to look at Genesis in several different arenas. One benefit of studying Genesis in this way is that some interesting patterns have come to light. At a Bible study a couple of nights ago, we were looking at Cain and Able. As the story goes, Cain ends up falling into sin, Able, the second born, is the one that God looks upon with favor. We see similar sets of brothers all throught the rest of Genesis (Ishmael and Issac, Esau and Jacob, Joseph and his brothers). So throughout Genesis, God is looking with favor on the second son. What really popped out about this is that, given Genesis is the book of beginnings, this pattern of the second son continues until we find the ultimate fulfillment in Christ. All throughout the book of Genesis, we see God points us forward to the second Adam. So the explanation of the two Adams in Romans 5 is a nice completion of the second son pattern in Genesis.