via The Easiest Way to Memorize the Bible: What I Learned from Dr. John Mitchell by Kenneth Berding

In fact, Dr. John Mitchell was over the age of 90 when he taught the two classes I took from him.  He continued to teach well into his mid-90s.  Not surprisingly, he was getting forgetful about some things by the time I had him as a teacher, but what he definitely was not forgetting were the Bible verses he had memorized.  His ability to recall Bible verses was astounding.  I do not know this for a fact, but I would guess that he had all of the New Testament and large sections of the Old Testament committed to memory.  All of his students were profoundly impacted by his immersion in the Scriptures.

I only had one opportunity to sit and talk with him while I was a student.  I had a single question to ask him that day:  “How did you come to memorize so much of the Bible?”

————–

Read more at the link above to learn what Dr. Mitchell did.