Luke 1:5-7
This is an interesting passage in that it says that Zachariah and Elizabeth lived a godly life (verse 6) and yet it also says they were childless (verse 7). In those days to be childless was considered to be a sign of sinfulness. In several verses in Deuteronomy 28 God promises children for those who are obedient. It seems that this would have troubled Zachariah and Elizabeth because it would not seem just unfair, but against a direct promise of God. No wonder they were so happy at the news that follows.
