The laugh of doubt and the laugh of joy
God called Abraham to leave his family and his home and go to a place God would later give his descendants. The problem was his wife Sarah was barren. He was 75 and his wife was 65. Years went by and they still had no children. Now he was 99. God spoke to him and told him the promise was about to be fulfilled (Gen 17). Abraham laughed and asked if child could be born to a 100 year man and a 90 year old woman. God responded that he was to name his son Isaac, which means laughter. Abraham laughed in doubt, so God made that the very name of his son.
Some time soon after, God came to Abraham in visible form with 2 angels and reiterated the promise (Gen 18). Sarah heard God speaking and now she laughed at the promise. God told her it was going to happen. When Isaac was born the next year, Sarah said, "God hath made me to laugh, so that all that hear will laugh with me (Gen 21:6)." This was not a laugh of doubt as if to say in modern lingo, "Yeah, right." It was a laugh of joy. Now the name Isaac no longer reminded them of their doubt, but of the faithfulness and power of God. It reminded them of the promises they had been waiting 25 years to be fulfilled. Their joy was threefold. It was a particular shame for a woman in those days to be barren. They were too old to physically have children. It was a miracle. It was almost as though they skipped having children and went right to grandchildren.
Sometimes God makes promises to us that we have a hard time believing. Sometimes we believe them at first, but it takes longer than we thought. Sometimes it doesn't happen the way we thought it was going to. We don't always see it. That is what faith is for. If we could see it, we would not need faith. Abraham is an example of faith, and is called the father of those who believe (Rom 4). The New Testament does not remember him as a man of doubt, but as a man of faith. We all have moments of doubt about our circumstances. As long as we do not give up our faith in God, we can overcome those moments. God can turn our laughs of doubt into laughs of joy as long as we do not give up.