The answer is: Paul

Galatians 4:22-31 - Paul uses Sarah and Hagar as symbols in his allegory, describing Sarah as the "free woman" whose children are heirs of the promise, contrasting with Hagar, the slave woman.

In the Letter to the Galatians, Paul dives deep into a layered discussion of freedom and bondage through the captivating narrative of Sarah and Hagar. Sarah, representing the covenant made with Abraham, symbolizes a life filled with promise and grace. According to Galatians 4:28, believers are likened to Isaac, Abraham and Sarah's miraculous child, born out of a divine promise rather than mere human effort.

On the flip side, Hagar stands as the representation of slavery and the law - the weaker, human-oriented attempts to fulfill God's promise, leading to all sorts of complications such as jealousy and conflict. It's fascinating to note that the name "Hagar" means "to flee," capturing the essence of her story. In turning back to Egypt in her flight from Sarah, it paints a picture of attempting to seek refuge in a place where promises were long discarded.

Historically, there have been interpretations that see Sarah's lineage as the origin of the Jewish people, while Hagar's line resultant from Ishmael contributes to Arab heritage. This duality highlights how these symbols transcend mere family lines, to express timeless truths about freedom, identity, and the divine—including how believers today navigate life in an ever-challenging world.

Thus, when Paul contrasts Sarah with Hagar, he's not just teaching theology; he’s invoking a powerful narrative to urge people towards a life of freedom through understanding rather than bondage. Cheers to that vibrant journey of understanding!