The theme Genesis is God, “In the beginning, God.” The book is about God. All the books of the Bible are about God. All of history is about God. Everything is about God. Genesis is not exhaustive; it does not tell us everything about God. The book of Genesis covers about 2,000 years of human history. It covers as much history as all of the rest of the Bible combined. Genesis is a selective telling of history by Moses. He gives the things that you need to know because they are most important and most related to our understanding of God. This leads you to what Genesis tells you about God.
The first information we have about God from Genesis is obvious:
God is [1:1]
There is not a long argument, just a statement of fact, “In the beginning, GOD.” He is. God exists as He is. He always was and is. God simply is.
However, God is not just simple, He is also complex. God is One [1:1, 26]. The Christian doctrine of the Trinity is that there is one God, and this one God is three equal persons—Father, Son, and Spirit [cf. Isaiah 48:16; Matthew 3:16-17, 28:18-20]. Although Moses might have understood the Trinity concept completely because of progressive revelation, therefore, the rest of Scripture teaches that each member of the Trinity was involved in Creation: the Father created 9Psalm 19:1; Acts 17:28; 1 Corinthians 8:6], the Son created [John 1:1-3, 10, 14; Colossians 1:16-17], and the Spirit created [Genesis 1:2; Job 26:13].
God did not keep silent about His creation and plans with creation. God is a talker [1:3a]. God spoke His creation into existence with the power of His words. God said and it was. God created light, stars, planets, plants and animals all by saying so. He spoke to His creation and charged them on how to live. God is verbal. If God talks, you must listen.
God make everything [1:3-25]
The question is not often whether God created everything [Hebrews 11:3], rather how did He create everything. For the sake of time and space, I will not indulge in a scientific treatise of Genesis and creation. Yet I will give you a few thoughts to chew on. First, there are differences in opinion among Christians as to whether God created a young earth [7 literal days] or old earth [i.e. gap between Genesis 1:1 and 1:2]. There are tensions because in Genesis 1-2 there is a mixture of history and symbols. Second, there are even more differences in opinion in the claims of science. Scientists have wrestled with the origins of the universe and human kind for millennia’s [i.e. Darwinism, atheism, intelligent design, irreducible complexity, etc.]. The theories and hypothesis among scientists come in all shades of colors, sizes and textures.
Let it be known, Genesis is not a scientific textbook, but what Genesis does tell us is enough—God created everything. This must be clear or Genesis 2 and following do not make any sense. Galileo said it well, “The Bible is not preeminently concerned with telling us how the heavens go. The Bible is, instead, most concerned with telling us how to go to Heaven.”
When God made everything He made it good [1:25]. God openly says, “Let there be this, and let there be that,” not half-heartedness or with reckless speediness. He did not make cheap trinkets that would easily fall apart. He created everything good. In the beginning there was no need for a policeman, fireman, garbage man or handy man. Everything was created good—without death, defect, or decay.
God rests after making everything [2:1-3]
Why did God rest? Did He get tired from using all His creative juices? No God is limitless in His creative powers. He does not need a break because of tiredness or vacation from stress. He rested the seventh day because He knew in His infinite wisdom that His created man would need this as an example to live by. Man is a finite creature and needs to rest weekly in order to remain sane and Sabbath. Rest is something God models and makes for man. Rest is best for mankind.
God gets glory for His greatness
Every molecule, ameba, moth, mosquito, Madagascar hissing cockroach, muskrat, monkey, moose, mouse, mountain lion, manatee, and man were created to give back praise to their Creator. God made creation to glorify Himself [Psalm 19:1]. God made creation to pour forth His love [Psalm 136]. God made creation for Himself [Colossians 1:16]. God made creation to show you His attributes [Romans 1:20]. And God made creation to worship Him [Revelation 4:11]. Everything was made by God and for God. Only “the fool says in his heart, ‘There is no God.’” [Psalm 14:1]
 Just Genesis 2, 3, 4, and 5, alone covers 1,656 years in a couple chapters.
 Cf. Deuteronomy 6:4; 2 Chronicles 15:3; Jeremiah 10:10; John 17:3; 1 Thessalonians 1:9; 1 John 5:20-21