Bottom line: A faith that judges God faithful will grow and experience the fulfilment of God's promise in His timing.

Sarah's demonstration of faith teaches us some very important lessons:

1) To live by faith, you must judge God faithful

2) To live by faith, you must overcome your unbelief

3) If you live by faith, you can experience the impossible (i.e. God's possible)

Sarah overcame her own unbelief. When she overheard God say that in one year she would have a child, she laughed. She literally laughed at what God said because she didn't believe. However, she overcame her unbelief as she judged God faithful. At the age of 90 she experienced the impossible. She gave birth to her firstborn son, Isaac. Isaac's name means laughter. She went from laughing at the promise to laughing with joy because the promise was fulfilled.