It is easy for us to miss the explosive tension in the events described in John chapter 8. The heat of the dialogue between Jesus and the Jewish religious authorities continues to escalate. And Jesus does nothing to lower the temperature. Indeed, he makes several statements that were direct assaults on the very identity of the ruling authorities. For instance, Jesus tells them that they are slaves in need of being freed by the truth concerning him. Imagine how insulted they must have been. Today Jesus would have been condemned for using intemperate speech.
But Heaven and Hell were in the balance. Men’s souls were at stake. So Jesus’ biting words were properly proportioned to the need of the moment. Specifically Jesus challenges the authority’s claims to be sons of Abraham. He directly challenges their paternity. They claimed that it was they who, because of their descent from Abraham, were the true sons of God. But Jesus turned the tables and states it is actually the devil who is their father. Jesus said this to men who had the means to kill him. And of course that is precisely what they would do.
The point Jesus is making is that those who have God as their Father are the ones who have Jesus as their Savior. Love for God is inseparable from love for the Son. God’s law, for all of its goodness and moral impeccability, cannot save a single sinner. Neither God’s law nor ethnic connection to Abraham can make anyone a child of God. For that miraculous transaction to occur there must be grace. There must be an atoning sacrifice for sinners. We become children of the Heavenly Father not by works of the law nor as a result of physical descent. Rather we become God’s children by way of his gracious adoption. We are not born children of God. Rather, we are made children of God by his own sovereign grace acting through faith in Jesus, the Son.