John 1:11 He came to his own, and his own people did not receive him.
22 Who is the liar but he who denies that Jesus is the Christ? This is the antichrist, he who denies the Father and the Son.
23 No one who denies the Son has the Father. Whoever confesses the Son has the Father also.
John 8:56 Your father Abraham rejoiced that he would see my day. He saw it and was glad."
1 What then shall we say was gained by Abraham, our forefather according to the flesh?
2 For if Abraham was justified by works, he has something to boast about, but not before God.
3 For what does the Scripture say? "Abraham believed God, and it was counted to him as righteousness." (Genesis 15:6)
Abraham acknowledged Christ, therefore he "had" the Father.
I have heard some claim that the Jews know God (Father), but have to learn who the Son is.
The scriptures are clear; if they truly knew the Father they would have then known that Jesus is truly the Son. As it is they rejected Christ thus proving that they never knew God, nor His Word. All who deny Christ deny the Father, and are of the spirit of antichrist
37 And the Father who sent me has himself borne witness about me. His voice you have never heard, his form you have never seen,
38 and you do not have his word abiding in you, for you do not believe the one whom he has sent.
39 You search the Scriptures because you think that in them you have eternal life; and it is they that bear witness about me,
40 yet you refuse to come to me that you may have life.
41 I do not receive glory from people.
42 But I know that you do not have the love of God within you.
43 I have come in my Father's name, and you do not receive me. If another comes in his own name, you will receive him.
44 How can you believe, when you receive glory from one another and do not seek the glory that comes from the only God?
45 Do not think that I will accuse you to the Father. There is one who accuses you: Moses, on whom you have set your hope.
46 For if you believed Moses, you would believe me; for he wrote of me.
47 But if you do not believe his writings, how will you believe my words?"
15 You judge according to the flesh; I judge no one.
16 Yet even if I do judge, my judgment is true, for it is not I alone who judge, but I and the Father who sent me.
17 In your Law it is written that the testimony of two people is true.
18 I am the one who bears witness about myself, and the Father who sent me bears witness about me."
19 They said to him therefore, "Where is your Father?" Jesus answered, "You know neither me nor my Father. If you knew me, you would know my Father also."