Roman Catholics are celebrating Jesus Christ’s Crucifixion and Resurrection this weekend, but for the Greeks its next week. Last year, however both churches joined together in one big Easter celebration on April 20.

The theological inconsistency of these two Easters is a problem causing a great deal of division as to when the real Easter should be. The World Council of Churches feels divided concerning this with a statement that points out that the division “compromises the churches’ credibility and effectiveness.”

The reason for the difference is that both the Western and Orthodox Christians believe that Easter is on “the first Sunday after the first full moon on and after the vernal equinox”, however the Western church uses the Gregorian calendar and the Orthodox churches use the older Julian calendar. And as if that wasn’t enough, there is also a bewildering array of ecclesiastical moons and paschal full moons in addition to the different calendars.

The  churches disagree on when the full moon is full with the Eastern Church setting the date according the actual astronomical full moon as seen along the meridian of Jerusalem where the Crucifixian occured. Furthermore, the Eastern Orthodox  Christians wants Easter to always come after Passover. For Catholics, Easter can precede Passover by weeks.