Judah and Tamar is an unsettling story for the modern reader. Brothers sleeping with family widows and dying because they refuse to get her pregnant. A widow dressing as a prostitute and tricking her father in law into getting her pregnant. A father acknowledging this chicanery as righteousness. What is a modern reader to do with such a story? How is Christ revealed in a pericope like this?
For those who quickly skip over the genealogies in Matthew and Luke, there is reason to go back and read them again, for in Matthew 1:3 we find the names of Judah and Tamar recorded in the family line of Jesus Christ. What is fascinating is that Judah had married outside of the family, he married a Canaanite woman (Genesis 38:2), thereby incorporating the unelect into the elect, the Gentile is melded with the Jew in this unholy union and Jesus becomes the savior of them both (Galatians 3:28).
The grace of God is magnificent, it comes to us even in the midst of sin and sinful situations. He can take human sin and depravity and bring about salvation. He can take human weakness and bring about strength. He can take the sinners of the world and bring about his plan for their salvation. Truly He is the Great and mighty God.