 This change became more universally accepted with the establishment of Roman emperor Constantine's Sunday law of 321 AD and the decree at the Council of Laodicea that in canon 29 declared that Christians should avoid work on Sunday.Seventh-day Adventists believe that prior to the beginning of human history, a challenge occurred in heaven between God and Lucifer (Satan) over "the character of God, His law, and His sovereignty over the universe" (Fundamental Belief no.8).