Why did God promise Abraham and Sarah a son for 50 years?
God promised Abraham and Sarah a son because out of that son would come the nation of Israel in fulfillment of the covenant promises. After about 50 years Abraham grew impatient, turned to the pagan custom of a surrogate mother, and Ishmael was born through Sarah's slave girl Hagar, creating the Middle East conflict.
Les explains that God had for 50 years promised Abraham and Sarah a son, because from that son would come the nation of Israel in fulfillment of the covenant promises. After about 50 years, Abraham got impatient and delved back into the pagan customs of using a surrogate mother. Sarah thought of it first and suggested a son by their slave girl Hagar; Abraham quickly agreed. From that fleshly idea came Ishmael, the natural son. Ishmael is still a child of Abraham, and this is the conflict in the Middle East today. Paul also says, '...neither because they are the seed of Abraham are they all children, but in Isaac shall thy seed be called.' Les notes that the Arab world says they are the true children of Abraham, because the Koran, as he understands it, puts the covenant promises with Ishmael rather than Isaac, so they feel they are the rightful owners of the Holy Land.