Jesus + Anything = Nothing (Part 9): The Contrast and Continuing Conflict Between Isaac and Ishmael

In Galatians 4:21-31, Paul illustrates his point to the Galatians by comparing the first two sons of Abraham. Ishmael, son of the slave Hagar, was born through human efforts to fulfill God's promise, Sarah's son Isaac was born through God's will. Are we children of Ishmael, slave to the law? Or are we children of Isaac, free because we place our faith in God?