Why are the numbers 6 and 7 significant in the Bible?

In the Bible, we see the significances of many numbers. However, the number 7 in the OT, and the number 6 in the NT draw the most attention. The number 6, represents, man, (Genesis 1:26), and wealth, (1 Kings 10:14), two aspects of the material universe that will eventually “pass away”. Furthermore, the “mark of the beast” as described in Revelation 13:11–18, is “six hundred, threescore, and six, (666), which further illustrates a number of imperfection as it is “the number of a man” (verse 18). These examples show that the number 6 represents the degradation of material things. The number 7 on the other hand, represents “completion.” In Genesis, 2:1–3, we see that God “rested” from his creation of the material universe, and in verse three, he “sanctified” the seventh day, and made it Holy. Furthermore in Exodus 20:8–11, God makes a commandment to the Israelites by the hand of Moses in the Ten Commandments, to keep the “Sabbath” day holy. Sabbath is a Hebrew word meaning “rest” or “cessation,” and represents the day that God rested from his completion of the creation of the material universe. Furthermore, we see various instances in the Bible where to atone for your sins, you had to sacrifice lambs, goats, and rams, many times by the “sevens”, in order for your prayer to be heard by God, (2 Chronicles 29:21). Furthermore, we see in Matthew 24:35, in the words of Jesus Christ, that the material universe shall pass away, but the eternal, perfect, and incorruptible “Word of God” (by which the material universe was created,) shall not pass away. In summary, the number 6 represents material things, degeneracy, and imperfection, and the number 7 represents perfection, completion, and the eternal nature of God.