In Genesis 2 we read, “And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made.” Genesis 2:2
God did not rest because He was tired. Genesis 17:1 calls God the “Almighty God.” Psalm 147:5 says, “Great is our Lord, and mighty in power; His understanding is infinite.” God is all-powerful; He never tires and never needs to rest. “Hast thou not known? hast thou not heard, that the everlasting God, the Lord, the Creator of the ends of the earth, fainteth not, neither is weary? there is no searching of his understanding.” Isaiah 40:28
God is the sum of perfection; He is never diminished in any way, and that includes being diminished in power.
When God said, “Let there be light,” the light appeared. He simply spoke creation into existence (Genesis 1:1-3). Later, we read about Jesus the Christ “Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high:” Hebrews 1:3
Forget the image of Atlas straining under the weight of the world on his shoulders. It’s not like that. The entire universe is held together by Gods’ word. The creation and maintenance of the universe is not difficult for God. A mere word will suffice. “For he spake, and it was done; he commanded, and it stood fast.” Psalm 33:9
The Hebrew word translated “rested” in Genesis 2:2 includes other interpretations than that of being tired. In fact, one of the main definitions of the Hebrew word shabat is “to cease or stop.” In Genesis 2:2 the understanding is that God “stopped” His work; He “ceased” creating on the seventh day. All that He had created was good, and His work was finished.
The context of Genesis 1–2 affirms the idea of God’s “rest” being a cessation of work, not a reinvigoration after work. The narrative tells us which things God created in each of the first six days. His power is displayed through the creation of the anthropic constants, light, mountains, seas, the sun, moon and stars, plant and animal life, and, finally, humanity. There are many parallels between the first three days of creation and the second three days. However, the seventh day is a sharp contrast. Instead of more creating, there is shabat. Instead of God “doing” more, He “ceased” from doing.
God did not merely “rest” on the seventh day; He “stopped creating.” It was a purposeful stop. Everything He desired to create had been made. He looked at His creation, declared it “very good” (Genesis 1:31), and ceased from His activity. In the Jewish tradition, the concept of shabat has been carried over as the “Sabbath.” The Law of Moses taught there was to be no work at all on the seventh day (Saturday). Because God ceased from work that day, the Israelites were to cease from their work on the Sabbath. Thus, the days of creation are the basis of our universal observance of a seven-day week.
Simply put, God’s “rest” was not due to His being tired but to His being completely finished with His creative work.