If you survey the internet you’ll find almost an infinity of ideas and warnings of the End-times — the period around the return of Jesus Christ. People speak of the “blood moons” — lunar eclipses — the last of which just occurred in April 2015. I believe the excitement here is related to the biblical symbolism of the phrase “moon turned to blood” found in Joel 2:31, and repeated in Acts 2:20:
Joel 2:31 The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the LORD come.
The “great and terrible day of the Lord” is the day of Christ’s return to rule as King. However, blood moons are astronomical phenomena, which occur like clockwork and can easily be predicted well in advance, because God has so ordered the heavens, like clockwork. The “sun turned into darkness” symbolises a solar eclipse, which also can be predicted like clockwork. However God does use natural occurrences as signs and symbols. He used a rainbow to symbolise a covenant with Noah that He would never flood the whole earth again. The rainbow was not new to Noah, but God gave it a new meaning (Genesis 9:13-16). And in Acts 2:19 we read,