Jesus has already revealed what is in their hearts. Now He reveals who their father is from a spiritual perspective. They are performing the deeds of their father who is the devil. This is why they do not know Him. They are not walking in the light as He is in the light. They say they are not illegitimate children. They go so far as to say that they have one Father who is God. Jesus counters by saying that if they had the same father, then they would accept His teachings. They would love Him. They would know that He came from the Father. Because their father is of darkness, they cannot see nor hear the truth.
Jesus speaks plainly. He boldly declares that their father is the devil (verse 44). They are doing the deeds of their father. Satan was a liar from the beginning, and they perform the deeds of their father. Their father never abode in the truth. He is not only the father of lies, but he is a murderer. They do not believe Jesus even though He speaks the truth. Those who are of God hear the truth. Since they are not of God, they cannot hear the words of truth.
The response from these Jews was very insulting. They called Jesus a Samaritan and he had a devil. Calling someone a Samaritan was saying that they were not a full-blooded Jew. Jesus’ response probably made them angrier. He said he did not have a devil. He honors His Father, and they dishonor Him. Once again, Jesus points to the fact that He does not seek glory for Himself. All the glory belongs to the Father. Jesus ends this passage by saying that if a man keeps His words, he will never see death.