Genesis 38 is not prescriptive; it is descriptive. And the main truth the passage describes can be summarized as follows: "Because God is faithful, His purposes will prevail."
What's Tamar doing in the genealogy of Jesus?
- Tamar's story highlights the nature of God's work of redemption. The hope of the gospel is not that God is making all new things, but rather that God is making all things new (Revelation 21:5).
- Tamar's story illustrates not only the type of people Jesus came THROUGH, but also the type of people Jesus came TO (that is, to save): sinners in desperate need of God's saving grace.
- Tamar's story - the story of a "forgotten woman" - illustrates a powerful gospel truth. Jesus came through a forgotten woman, and as he died cried out, "My God, my God, why have you forsaken me?" in order that those who trust in Jesus would know that they are NEVER forgotten by God.
Hebrews 13:5-6 is true of all those who trust in Jesus: "I will never leave you nor forsake you...The Lord is my helper, I shall not fear; what can man do to me?"