Back in 2008 Christian pastors Mark Blitz and John Hagee (whose endorsement of John McCain for President that same year seen by some as anti-Catholic caused headaches for the campaign) popularized the idea that a tetrad (or a series of 4 lunar eclipses), starting with last nights blood moon, is a sign of either the second coming of Christ (according to Blitz) or change in the course of history for Israel (according to Hagee). However the prediction has been criticized by both Christian and secular sources alike. Furthermore, many theologians believe it's extremely unlikely that a lunar eclipse that can't be seen in Jerusalem would be a sign of anything.

Both Hagee and Blitz believe that the rarity of tetrads (all coinciding with Passover or Sukkot) is evidence that a major change in the course of history is afoot. However Bruce McClure and Deborah Byrd, both writing for Earth and Sky magazine, point out that the Jewish calendar is lunar which means that one sixth of all lunar eclipses will occur during one of these holidays. According to Wikipedia there have been 62 tetrads since the first century A.D. and 8 of them have coincided with both feasts proving these events aren't as rare as Hagee and Blitz have implied.

For centuries people have been looking for signs pointing to the second coming of Christ. If you believe in the bible though you may want to stop looking for signs though because it clearly states in Matthew 24:42 "Keep awake therefore, for you do not know on what day your Lord is coming" implying that no one will know when it will happen making Blitz' claims look inaccurate at best. Hagee doesn't go quite as far as Blitz in his predictions though, giving himself more wiggle room. Even according to Christians though, his claims appear specious at best.