Was Abraham justified by obedience or by faith?

Having provided a technical definition and explanation of justification by faith in Romans 3:21-31, Paul now turns his attention in Romans 4 to the experience of Abraham. Paul specifically refers to Abraham seven times in the course of the chapter—a rather large number considering Abraham is only mentioned nine times in the entire book and only eighteen times in all of Paul's letters. For Paul, Abraham becomes a key example of what it means to live by faith. But this leads to an interesting question:

1. Besides Abraham, what other individuals in the ...