The Reason for the Sabbath
The Bible states two reasons to keep the Sabbath. The first reason is taken from Creation. Exodus 28 states that God rested from his labors on the Sabbath. Therefore, humans, should also rest from their labor. The second reason stems from redemption. God redeemed the Israelite's from their bondage in Egypt. Therefore based on Deuteronomy 5 God's people should worship God for his acts of redemption. Historically the majority of Christians do not observe the Sabbath, which is the seventh day of the week, Saturday. Instead they tend to observe Sunday the day of Christ's resurrection, as a time of worship and rest. Enjoy your Sabbath.
The Book of Exodus
Exodus means a going out. Broadly speaking this second Book of the Pentateuch teaches that redemption is essential to any relationship with a Holy God. As Exodus shows us even a redeemed people can not have fellowship with God unless they are constantly cleansed from the defilement of sin. Answered prayer is dependent on purity. (Psalm 66:18)
Exodus also presents Moses as a mighty intercessor. The powerful intercessions of Moses were more than a match for the murmurings of Israel against their God.
Being called by God — Moses
As we look through the history of the Bible, when people are captured by a false idea or enslaved by a tyrant, God speaks to a single person, flawed by imperfection, who hears the unmistakable call of God.
Moses was at work keeping the flock of sheep under control for his father-in-law Jethro when his call came. The strangeness of the bush which did not burn up caused Moses to turn aside. The call of God has two sides to it, the voice of God and the willingness to hear God calling us by name. In the beginning Moses made excuses. I can not do what you ask. Yet God did not give up on Moses. When God calls to you will you yield to his will?