In the original Hebrew manuscripts of the Old Testament there were no names or titles to the various books. The Jews, to whom God gave His Word, usually called each book by the first one or two words of the opening sentence. In Genesis the first word in Hebrew, the original language of the Old Testament, was the word translated “In the beginning”, and so that is what the Jews called it. Many centuries later Jewish scholars translated the Old Testament into the Greek language and gave names to each of the books. This translation is called the Septuagint. Much later these names were used in the Latin translation of the Bible, and many centuries after that in the English translation of the Bible. In this way the names came into what is now called the King James Version and other English versions.
The people of Israel from the time of Moses onward were sure that Moses wrote the first five books of the Bible, and there is strong evidence in the Bible itself to support this belief. See Ex 17:14; 24:4; 34:27; Num 33:2; Deut 31:19,24-26; Josh 1:8; 8:31; 1 Kings 2:3; Luke 24:44; 1 Cor 9:9. Most importantly, Jesus Christ Himself said that Moses wrote about Him. See Matt 19:8; John 5:46,47; 7:19.
Probably sometime between 1446 and 1406 before Christ.
Beginnings. Here we have the beginning of God’s written revelation of Himself, the beginning of the world, of mankind, of sin, of God’s plan of redemption, of the various races of men, and the beginning of the people of Israel through whom God gave His Word.