In Stephen’s testimony just prior to his martyrdom in Acts, he gives an account of Moses which does not appear in our version of the Old Testament. In Stephen’s explanation, he attributes to Moses the knowledge that he was going to be a deliverer of Israel even before he killed the Egyptian. (See Acts 7: 24-25.) According to Stephen, Moses was frustrated that the Israelites failed to recognize him as their deliverer.
Our account instead tells us that Moses was called by God, to his surprise. When called, Moses responded: “Who am I, that I should go unto Pharaoh, and that I should bring forth the children of Israel out of Egypt?” (Exo. 3: 11.)
This goes to show that there were different traditions reflected in the biblical accounts. Just as there are references to scriptural books which we no longer possess.
The relevance of personal revelation, and the need for continuing revelation, remain apparent even if you want to understand the very scriptures we believe in. Hence the almost immediate reaction of Joseph and Oliver to receiving the Holy Ghost and how scriptures took on new, even previously hidden meanings. (See JS-H 1: 74.)
I was taught from the New Testament all my childhood by a mother who was a Baptist. When hands were laid upon my head after baptism, I re-read the New Testament and thought it was a new book.