Photo of a church's advertisement of Sunday worship, but is Sunday God's day or is it Saturday? Bible under low key lighting liorpt/iStock/Thinkstock, empire331/iStock/Thinkstock Matthew 28:1 Pic of unleavened bread, which we are commanded to eat during the Days of Unleavened Bread. (PCOG/Brooke Davis) A photo of Israelites fleeing Egypt, on a Night to Be Much Observered. Photo of Garden Tomb points out that God's sacred calendar is important in proving the dates of Christ's death and resurrection. Photo of a lamb, used by ancient Israel in their Passover observance. Julius Schnorr von Carolsfeld Photo of a halloween pumpkin, a tradition for the pagan holiday.