Lesson 14: Isaac

  • The Birth of Isaac
  • Ishmael is Cast Out
  • Introduction to Types in Scripture
  • Abraham's Faith is Tested
  • Comparing Scripture with Scripture
  • Substitutionary Sacrifice


Abraham had waited many long years for God to fulfill His promise of a son by Sarah. Now, at the threshold of his hundredth year, his patience was about to be rewarded. In Genesis 17:21, God spoke to Abraham and said, "But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year." Although Abraham would later have many children, the Bible specifies that Isaac was the fulfillment of God's promise to Abraham, and it was through Isaac's lineage that God would bless all the nations of the world.

Ishmael, while certainly a legitimate son of Abraham, was an ordinary child whose birth came about as a result of man's efforts. But Isaac's birth was miraculous, made possible only by God's direct intervention. At the time of Isaac's conception, not only was Sarah well beyond the age of fertility, but Abraham himself was no longer able to produce seed. (See Romans 4:19) God waited until there was no possible way for His promise to be fulfilled by human endeavors, and when His time had come, He provided the heir of His choosing, the child of promise who would continue the line of Messiah.