Hebrews 11:8-19 8By faith Abraham, when he was called to go out into a place which he should after receive for an inheritance, obeyed; and he went out, not knowing whither he went. 9By faith he sojourned in the land of promise, as in a strange country, dwelling in tabernacles with Isaac and Jacob, the heirs with him of the same promise: 10For he looked for a city which hath foundations, whose builder and maker is God. 11Through faith also Sara herself received strength to conceive seed, and was delivered of a child when she was past age, because she judged him faithful who had promised. 12Therefore sprang there even of one, and him as good as dead, so many as the stars of the sky in multitude, and as the sand which is by the sea shore innumerable. 13These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth. 14For they that say such things declare plainly that they seek a country. 15And truly, if they had been mindful of that country from whence they came out, they might have had opportunity to have returned. 16But now they desire a better country, that is, an heavenly: wherefore God is not ashamed to be called their God: for he hath prepared for them a city. 17By faith Abraham, when he was tried, offered up Isaac: and he that had received the promises offered up his only begotten son, 18Of whom it was said, That in Isaac shall thy seed be called: 19Accounting that God was able to raise him up, even from the dead; from whence also he received him in a figure. My 2 cents.

He was considered the Father of the Jews because the nation of Israel can trace their ancestry back to Abraham. God was faithful in his promise to Abraham that he would be the father of many nations (Gen. 17:5). And Jews throughout Biblical history felt that they were superior because they had the Law from God, the Covenant of Circumcision, and that Abraham was their father. And New Testament writer and Old Testament "scholar," Paul, comes along in the Book of Romans and says: "If, in fact, Abraham was justified by works, he had something to boast about—but not before God. What does the Scripture say? "Abraham believed God, and it was credited to him as righteousness." Is this blessedness only for the circumcised, or also for the uncircumcised? We have been saying that Abraham's faith was credited to him as righteousness. Under what circumstances was it credited? Was it after he was circumcised, or before? It was not after, but before! And he received the sign of circumcision, a seal of the righteousness that he had by faith while he was still uncircumcised. So then, he is the father of all who believe but have not been circumcised, in order that righteousness might be credited to them. And he is also the father of the circumcised who not only are circumcised but who also walk in the footsteps of the faith that our father Abraham had before he was circumcised. It was not through law that Abraham and his offspring received the promise that he would be heir of the world, but through the righteousness that comes by faith. For if those who live by law are heirs, faith has no value and the promise is worthless, because law brings wrath. And where there is no law there is no transgression. Therefore, the promise comes by faith, so that it may be by grace and may be guaranteed to all Abraham's offspring—not only to those who are of the law but also to those who are of the faith of Abraham. He is THE FATHER OF US ALL." (Romans 4:2-3, 9-16) So Paul is saying, Abraham was justified by his faith in God, not the Law or Circumcision. So all those who have faith in God like Abraham are called his children and thus Paul includes the Gentiles into the Family of God and the Family of Faith. Hope this helps! God bless!

Wasn't he the guy that ALMOST killed his son because God said to but was spared at the very last second? Thats freaking faith if I have ever seen it!

Because he is the father of Juddism and Christianity by being the first to believe in the one and only God of the Bible.