Sarah’s faith embraced God’s miracle power to conceive even though she was barren and was past the age of childbearing, for the authority of her faith rested in the One who made the promise, and she tapped into his faithfulness.
“Then God entered into covenant with Abraham, which included the requirement of circumcision. So when he became the father of Isaac, he circumcised him eight days after his birth.
Then one spoke up and said, “I will return about this time next year, when your wife Sarah will certainly have a son.” Sarah overheard it, for she was at the tent door not far behind him.
God said, “Listen to me. I promise that you and Sarah will have a son, and you will call him Isaac. I will confirm my everlasting covenant of love with him and his seed.
I took your father Abraham from that land and led him through all the land of Canaan. I gave him a son, Isaac, and through Isaac I multiplied his descendants.