I. Abraham had two sons (Genesis 15 and 16)
A. Now this may be interpreted allegorically
1) Allegory: a term for a figure of speech. It is a story or picture with a hidden meaning. The characters in allegories are symbols which represent particular ideas. Example: Aslan the Lion in Chronicles of Narnia. The story has a figurative meaning, not just a literal one.
2) Slave son: “Under the law” “according to the flesh”
a) Using the law as a means of being justified to God. Not the intent of the law.
3) Free son: “Child of promise” “born through promise”
a) Relying on God’s word that He will get us home. “The righteous shall live by faith” Paul uses this in Galatians 3:11 (And Romans, and Hebrews) but it comes from Habakkuk 2:4, “"Behold, his soul is puffed up; it is not upright within him, but the righteous shall live by his faith.”