God appointed the seventh-day Sabbath as a day of worship. What day of the week is the Sabbath, the seventh day? Calendars, dictionaries and even Catholic books manifest that the seventh-day Sabbath is Saturday. Through the Bible, we can confirm that the forefathers of faith, Jesus, and His disciples all kept the seventh day Sabbath, which God commanded us to keep as a worship day. Then why does every church not keep the seventh-day Sabbath but keep the first-day Sunday?