The great contribution of this book is the revelation that Yahweh is the sovereign God who provides deliverance for man from the slavery in which he finds himself.
The major teaching of Exodus is primarily threefold.
1. The sovereignty of God.
2. The salvation of man.
3. The methods by which the sovereign God affects man's salvation.
First, Exodus teaches the sovereignty of God.
In Genesis we learned that the only way we can realize the purpose for which God created us is through faith in a trustworthy God that expresses itself in obedience.
In Exodus we learn that the God with whom we can have a relationship is not only trustworthy but sovereign. This realization should produce within us the double effect of worship and obedience.
Sovereignty is the attribute of God that expresses the fact that Yahweh is the ultimate ruler of the universe. There is no one higher in authority than He. As sovereign, He has all power. Sovereignty does not refer to how God rules, the method by which He governs. In particular, it does not imply that God controls every detail of life immediately (directly). God exercises His sovereignty by allowing human beings certain freedoms. He does not control us like puppets on strings but as a father controls his children. We have limited freedom.
We can see God's sovereignty clearly in His superiority over all the so-called gods of Egypt. He displayed His great power in all of His activity that resulted in the liberation of the Israelites and His adoption of them as His people. Scripture teaches both the sovereignty of God and the responsibility of man. No one has been able to explain this mystery adequately (cf. Job).
Second, Exodus teaches the salvation of man.
In Genesis we saw the need for salvation (i.e., the Fall and the repeated failures of man).
In Exodus, God revealed the method of salvation and explained the consequences of salvation initially.
Exodus teaches that God provides salvation for man. Man does not provide it for himself. It also reveals that man appropriates what God has provided by faith.
Two activities become prominent as major expressions of faith in Exodus: worship and obedience. Worship and obedience are the Godward and the manward expressions of faith respectively.
Worship consists of putting God at the center of life (cf. Rom. 12:1-2). Worship was to characterize the Israelites nationally and personally. God illustrated the importance of placing Him at the center of life by locating the ark of the covenant in the center of the tabernacle. He further did so by placing the tabernacle in the center of the Israelite camp.
Obedience consists of arranging all the parts of life in proper relation to God who is at the center. If something in life does not orient toward God properly, there is disobedience. In this way Exodus deepens the revelation concerning obedience that God has given us in Genesis.
Third, Exodus teaches the methods by which the sovereign God affects man's salvation.
God's method of dealing with the human race generally (outside Israel) was by creating a pattern, namely, the nation of Israel. God created the nation of Israel so that He could demonstrate through Israel for all other nations and peoples to see how glorious it can be to live under God's government. God's election of Israel was not the selection of a pet that God would favor at the expense of all others. It was the construction of a pattern. Israel was to be a demonstration to all the world of how wonderful life can be under the rule of Yahweh (cf. 19:5-6).
God's method of dealing with Israel was by revealing a person, namely, Himself. In many revelations to the Israelites, God sought to deepen their understanding of and appreciation for Himself and His will. The special privilege of receiving the revelation was a blessing to them and should have resulted in their being a blessing to the whole world. Israel was to do this by demonstrating how good it is to live under God's kingship. Some of the most important revelations occur in the following passages: 3:4-16; 6:2-8; 19:3-6; 20:1-7; 24:1, 9-11; 34:5-8; and 40:34-35. They are not all different, but God intended them to have the cumulative effect of deepening the Israelites' concept of God. They came to the people like waves beating on the shore. All the details of the Mosaic Code, which begins in Exodus and continues through Numbers, reinforce the main point of this revelation, which is the character of God.
God's method of dealing with individuals was by providing opportunities, choices.
We can see this most easily in God's dealing with the two major characters in Exodus, Moses and Pharaoh. God's method of dealing with both men was the same, but their responses were different and consequently so were their fates.
Pharaoh was a strong, wise leader who acted wholly by sight rather than by faith in Yahweh. He is typical of people of the world. God's method of dealing with him was to give him opportunities to make the right choices and so experience the blessing of God. Pharaoh chose not to trust God, and his disobedience resulted in personal tragedy for himself and national tragedy for Egypt.
Moses on the other hand was also a strong, wise leader, but he acted by faith rather than by sight (Heb. 11:27). God's method of dealing with him in Exodus was the same. He gave him opportunities to make the right choices and so experience God's blessing. Moses chose to trust and obey God, and his life is a story of personal triumph and national triumph for Israel.
In both cases God patiently worked with these representative individuals and gently encouraged them to do His will. Moses developed into a noble character because he chose to submit to God's government even though he was faulty, failing, and fearful. Pharaoh was a more admirable person in many respects, but he sank into destruction because he chose to refuse to submit to God's government (authoritative rule).
Exodus teaches that individuals are personally responsible under God, and their choices determine their destinies. There is ample New Testament evidence for this in John 1:12; 3:16, 36; 5:24; 6:47; 20:31; et al. Divine sovereignty does not negate human responsibility.
If we look at the record of God's activity in Exodus, we see progress. The unbelief of His enemies does not frustrate Him. His ultimate purposes for Israel came to fruition.
However if we look at the record of man's activity in this book, we see failure. Even Moses, Aaron, and the Israelites who trusted God constantly failed. We observed this in the lives of the characters in Genesis as well.
While man constantly falls short of what God requires, human failure does not frustrate God's ultimate purposes. This proves that God is indeed sovereign.