Why is the date on which Easter is celebrabrated dependent on the lunar cycle?
In the days of Christ, there were no calendars, and so they marked time by the sun and the cycles of the moon. It was not recorded “Christ was crucified or ressurrected on April 3rd” or any specific date, just that these events happened at certain points in the lunar cycle, on the Sabbath after the full moon, after the spring, kind of thing. So to be really accurate, they celebrate it on that schedule, rather than a specific date.