THIS MIGHT SURPRISE YOU
The answer
Abraham. Genesis 15:6 — "Abraham believed God, and it was reckoned to him as righteousness" — is quoted by Paul in Romans 4:3 and by James in James 2:23. Paul reads it apart from works; James pairs it with Abraham offering Isaac.
Why it’s interesting
Two canonical writers, arguing in different directions, chose the identical proof text. Whether James knew Paul's letters — or a slogan derived from them — is itself debated; the shared verse is why the two chapters have been read together for centuries.
Scholarly consensus
You can know the Bible.
Not just the stories, but the history, authorship, and scholarship behind it.