There are conflicting traditions of the faith of Abraham as well as doublets describing the other patriarchs in Genesis, demonstrating the existence of multiple authors and multiple sources for the first five books of the Bible. The stories were polemical and this is best demonstrated by the conflicting portrayals of the story of faith in the different polemics. For example, God made a covenant with Abraham promising him descendants like the number of the stars, and, "Abraham believed God and it was credited to him as righteousness ... Thatday God made a covenant with Abraham." (Genesis chapter 15 verse 6, verse 18) In Genesis chapter 17 Abraham is informed that God wanted to make a covenant with him. This is an alternative tradition to the one described in Genesis chapter 15, and the assumption is that no covenant was made at that time, in that the reason for God's appearance was to make a covenant. God promised to make him the father of nations. Abraham did not believe God. "Abraham bowed low and laughing to himself said, ‘Can a son be born to a man who is a hundred years old? Can Sarah bear a child at ninety?'" (Genesis Chapter 17 verse 17) It is interesting to note that in the book of Romans in the Church Testament, Paul uses the former passage for the purpose of building a theological argument based on faith, and he clearly ignores the alternate tradition. "In the presence of the God in whom he believed ... In hope he believed against hope, that he should become the father of many nations; as he had been told ... He did not weaken in faith when he considered his own body, which was as good as dead because he was about a hundred years old, or when he considered the barrenness of Sarah's womb. No distrust made him waver concerning the promise of God, but he grew strong in his faith as he gave glory to God, fully convinced that God was able to do what God had promised." (Romans chapter 4 verse 18) The purpose of Paul's use of this passage is to demonstrate that 'righteousness comes to those who believe.' I, however, have an alternative interpretation of these two contradictory polemics. Whether you believe God, and it is 'credited as righteousness,' or whether you don't believe God, and laugh, the baby is born either way. To be fair, I should acknowledge that there are passages in the Church Testament which acknowledge 'the two Abrahams.' "What if some did not believe? Will their faithlessness nullify the faithfulness of God. Certainly not." (Romans chapter 3 verse 3) So don't worry about our unbelieving Abraham. That laughing will not nullify the faithfulness of God. The baby will born despite his obvious unbelief. "For God is the savior of everyone, but especially of those who believe." (1 Timothy chapter 4 verse 10) The two allegories of the faith of Abraham
(But I digress.)