John 8:42-43

The true ancestry of the Jews: V. 42. Jesus said unto them, If God were your Father, ye would love Me; for I proceeded forth and came from God; neither came I of Myself, but He sent Me. V. 43. Why do ye not understand My speech? Even because ye cannot hear My Word.

The Jews had vehemently repudiated the idea of their being idolaters and had just as emphatically insisted that they were children of God, that they belonged to God's house as children.

But Jesus now shows that God can not be their Father. For if that relationship obtained, then it would follow without fail that they would love Him, since He proceeded forth from eternity from the Father. He did not come on a mission of His own scheming and devising, but God has sent Him. If they were really children of God, they would love Him, for brothers must feel brotherly love toward one another. He that does not love Christ has no part in God.

And not only the fact that they refused to welcome Him was an unmistakable argument against their being God's children, but also the fact that His speech was incomprehensible to them, that they could not understand the commonest things concerning the Father which He told them. The ears of their mind, of their understanding, were closed. Even the substance of His words was foreign to them; His language, His mode of speech, everything was strange and unfamiliar to them.

For that reason they also refused to give ear to His preaching. Unbelief has its cause and reason in not wanting to accept Jesus and His doctrine.