A second reason: The only event Jesus specifically instructed his followers to commemorate was his death, not his birth, and this was to be done as a simple communion meal.
Lebaka la bobedi: Tiragalo e le nngwe fela e Jesu a laetseng barutwa ba gagwe ka tlhamalalo gore ba e gopole ke ya loso lwa gagwe, e seng letsatsi la gagwe la botsalo mme e ne e tshwanetse go nna tiragalo e e sa raraanang ya selalelo.