Charles, have you read Jubilees? If you believe that angels told Moses everything on Mount Sinai then he wrote it down, it explains why those books are written by Him but not all witnessed by him. Another explanation is that the stories found in Genesis were an oral tradition passed down through the generations of men, and Moses just wrote them down. The Talmud says that Moses wrote Job, but I note that they were post-Christ Jews, therefore making them anti-christs, and possessors of the spirit of falsehood.
"All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness" 2 Timothy 3:16
"Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost. 2 Peter 1:20-21
It means NOTHING about what man's opinions are without testing it with Scripture. If it does not match the Word, it is a LIE.
"To the law and to the testimony: if they speak not according to this word, it is because there is no light in them." Isaiah 8:20