Are you from a functional family? Some of my favorite childhood television shows were about happy families. Leave it to Beaver. Father Knows Best. The Brady Bunch. All seemed functional.
Can you think of a functional family in the Bible? What about Adam's family? Or Noah's? Abraham's family became the nation of Israel. Still, they had their problems.
Again, Genesis is descriptive not prescriptive. The story contrasts two of Jacob's or Israel's sons. Generational favoritism persisted. Jacob favored Joseph. Led by Judah, Joseph's brothers sold him into slavery. Judah failed to provide his son Shelah to give his widowed daughter-in-law Tamar a family. Later he fathered twin sons through her.
Knowing one of Jacob's twelve sons would be Jesus' ancestor, which one would you choose? At this point, I'm thinking Joseph. But God chose Judah. In fact Perez, one of Tamar's sons became Jesus' ancestor. Amazing.
Good news: God can work through broken families. My friend used to say God can hit a straight lick with a crooked stick. All the sticks are crooked in our world. The fall has affected us all.
In truth, God only has broken people to work with. This should not encourage us to make a mess of our lives. But it does give us hope. God is not finished with our families, yet. Judah's descendant Jesus died for our sins. God longs to forgive us. His kindness leads us to repentance.