Israel in Exodus and we, in the current world, are children of God—the same Father, the same family. So Exodus is our family story, see for example, 1 Corinthians 10:1 which refers to our fathers. Israel’s disobedience is an example for us to stand firm in faith (1 Corinthians 10:6–11).
Israel is God’s firstborn son. That involves more sons (peoples) will follow. And indeed, the blessing for Abraham is for all peoples (Genesis 12:3). That promise is fulfilled by Jesus; whoever believes in him receives the blessing (Galatians 3:8, Galatians 3:14). If you are Christ’s, then you are Abraham’s offspring, heirs according to promise
(Galatians 3:29). We will inherit the earth and we will be in God’s kingdom (Matthew 5:5, Matthew 5:10).
22 Then you shall say to Pharaoh, ‘Thus says the LORD, Israel is my firstborn son,