"At last I have an opportunity to post something substantial. I apologize in advance if I don't answer everything you've posted. I stand in awe of the amount of time you and Biblicist put into writing on this forum. You must either type very quickly or have a lot of time on your hands.
No, Abraham is not my father.
Well I think you'll find he is.
Paul stands more as a "father" to me
That is because you are not believing the Bible. Paul is never described as the father of all who believe; Abraham is. I could really stop there. Your error is already made manifest.
However, to continue:
First of all may I raise my hand and say that I have Abraham's spiritual DNA. No doubt about it. Abraham is my spiritual father. How do I know that? The Bible tells me so.
Before I start, let me say that my guiding hermeneutical principle is that
all Scripture is about the Lord Jesus Christ.
"These are [the Scriptures] that testify of Me' (John 5:39; cf. v. 46).
'And beginning with Moses and all the prophets, He expounded to them in all the Scriptures the things concerning Himself' (Luke 24:27; cf. Luke 24:44-47). It's all about Jesus.
So what do we mean when we say that Abraham is the father of believers.
'Know then that those who are of faith, it is they who are sons of Abraham' (Galatians 3:7). To be
'of faith' means to have trust in God as one's guiding principle. When this can be truly affirmed of people, then they are sons of Abraham; and if sons then also heirs and partakers of the spiritual promises made to Abraham. In Gal. 3:7, there is an emphasis that believers alone, but all believers, are sons of Abraham.
Not physical descent but spiritual likeness makes one a son of Abraham. Our Lord told the Jews,
"If you were sons of Abraham, you would do the works of Abraham' (John 8:39; cf. also Matthew 8:11-12 & Luke 19:9). What were Abraham's works?
'He believed in the LORD and He accounted it to him for righteousness' (Genesis 15:6, NKJV. Compare this with John 6:28-29). Just as it is the case that to be a child of God one must be like God (Ephesians 5:1; 1 John 2:29; 1 John 3:1, 8-9), so it is also the case that to be a son of Abraham one must be like Abraham and do his works, thus partaking of his blessedness. That is what I mean by having Abraham's spiritual DNA.
What did Abraham believe? Well he believed the Lord, both His commands (Hebrews 11:8) and His promises (Hebrews 11:13). True faith always results in action. If someone says to me here in England, "It's going to rain tomorrow," what will be the evidence that I believe him or not? Surely it whether I take a raincoat or an umbrella with me when I go out. If I say to myself, "Nah! I don't think it's going to rain," I shall display my lack of faith in that forecast by going out without either. My works will be the evidence of my faith.
What promises did Abraham believe? He believed the Gospel.
'And the Scripture, foreseeing that God would justify the Gentiles by faith [faith in what? Faith in Christ!]
preached the Gospel to Abraham beforehand, saying, "In you shall all the nations of the earth be blessed"' (Galatians 3:8). So Abraham knew the Gospel. Who else is a blessing to all nations but the Lord Jesus Christ?
A little later, Abraham met Melchizedek. This man is described as being king of righteousness and king of peace. Most significantly IMO, he brings no animal sacrifice, but bread and wine, the emblems of our Lord's passion. Whom else do you know who is
'beyond all contradiction' (Hebrews 7:7) greater than Abraham. Either Melchizedek is a theophany or a type of the Lord Jesus Christ. He blesses Abraham as
'possessor of heaven and earth' (Genesis 14:18-19; cf. Romans 4:13). Whom else do we know who is going to possess heaven and earth? Why those who are the sons of Abraham; those who are of faith.
'Blessed are the poor on spirit, for theirs is the kingdom of heaven........ Blessed are the meek, for they shall inherit the earth' (Matthew 5:3-5).
I have asked a very simple question numerous times in these debates, and while I think I have asked you, whether or not I have, I will ask you now...
...is the Jew today, who understands the First Principles of Christ and trusts that Messiah will redeem Israel...
...saved?
Only if he has the faith of Abraham and sees in the OT Scriptures Christ crucified, risen and ascended (1 Corinthians 15:1-4). It's all there for him.
Is faith in God through His Word enough for a man to be reconciled to God on an Eternal Basis?
Only if that faith in God includes faith in the Lord Jesus Christ (see above). Abraham saw Christ with the eye of faith.
'Your father Abraham rejoiced to see My day, and he saw [it] and was glad' (John 8:56).
[concerning Galatians 3:1-3] Paul is preaching Christ crucified, and the passage is not centred on justification by faith, but, receiving the Spirit of God by the hearing of faith. That is specific to this Age, Martin. Abraham did not receive this Promise, that is...the Promised Spirit. He did not come until Pentecost (Acts 1:4-5).
I know this is going to open a huge can of worms and it will need a separate thread, but Abraham and all other OT saints received the Holy Spirit (eg. Psalm 51:10-12; Isaiah 61:1; Matthew 16:17; Luke 2:25-27). At Pentecost, the Spirit was sent forth more widely and in greater power, but He was not sent forth for the first time. Abraham's faith is the same faith that we have- wrought by the Spirit. The prophecy of Amos concerns the Spirit being poured out on
'all flesh'- Jew and Gentile alike.
'Now if anyone does not have the Spirit of Christ, he is not His' (Romans 8:8). That applies all through the O.T as well as the NT.
What you are saying, and this is no misrepresentation, is that unless I agree with your perspective I will remain in error.
Exactly so, but of course, there is no need at all for that to happen.
Now think about this: why did God make promise unto Abraham? Because he believed God?

Abraham could not believe God until God had spoken to him.
No...God intended to redeem mankind the same Way all along. Was Abraham justified because he trusted Christ as Saviour?
Yes absolutely! He looked forward with the eye of faith and saw Christ's day. He knew the Gospel.
'So then those who are of faith are blessed with believing Abraham' (Galatians 3:9). You are either blessed with Abraham or you are not
'of faith.' QED.
I'm sure I haven't answered all your questions, but the thread has grown so monstrously long that it's taking me too long to find them. Now it's back to my sermons.