In John 8 Jesus debates the Jews — Jews who believed Him! He has claimed He has been sent by the Father. Starting in John 8:31, Jesus tells them that by abiding in His word they will know the truth and will become free. Then, in John 8:33, they rebuke Him, saying they have never been enslaved to anyone (very conveniently forgetting Egypt, periods under both their judges and kings, captivity in Babylon, and that they are then ruled by Rome).
They claim they are from Abraham and sons of God. The point Christ makes is that they are not acting like Abraham, they are acting like the devil (John 8:44).
Our fruits are ultimately known, not by what kind of tree we say we are, but by actually bearing fruit and the type of fruit it is. Jesus proclaims “By this my Father is glorified, that you bear much fruit and so prove to be my disciples.” in John 15:8.
If someone we claim to be loyal to and love asks us time and time again to do something, but we refuse, make excuses, and keep telling them how very much we love them, eventually everyone around will discover the truth: that our words mean nothing and our actions show what is in our heart. Like the father with two sons, the one who does the will of the Father will be the one pleasing to the Father (Matthew 21:28-32).
We can claim to be children of God all we want, day after day, but if we do not do His works, we are not His. Our actions speak loudly about who we are really children of.
— Stefan Richardson