We are to assume that every word in the Bible is important. Or so I assume.
However, I think we can all agree that a verse like John 8:32 ("You will know the truth, and the truth will make you free") is more important than one of those Old Testament passages about Mehishbopheth begetting Ziklag.
I've made a list of about 300 Bible verses that are the "most memorizable." I have, in fact, memorized most of them. They're all in "tweaked NIV," that is, NIV with corrections where needed (the NIV is a second-rate translation). They are not listed in any particular order.
Sometimes I imagine one of these 49-year-old Christians dying and going to stand before God. This is a person who has never been in poverty or want; he spent $69 on his leather-bound "Archaeological Study NIV Bible (with Footnotes)" that he takes to church with him every week.
God looks at his list of names and says, "Let's see ... Elwood Bartholomew Griffin ... you were a Southern Baptist, right?"
"Yessir, I was. And, uh, everybody called me 'Bud'."
"So Elwood ... your church's doctrine is based on the Bible alone, right? Sola scriptura?
"Right!" Bud realizes that this is the only Latin expression he actually knows.
"And you were saved 32 years ago, right?"
God seems to be thinking to himself. "Do you think it would be too much to ask that my people, who are called by my name, would memorize the Bible just a little bit?"
"Uh, nosir. Not at all."
"Thirty-two years. Would it be too much to ask that you might have memorized ... one verse per year - chapter and verse - and be able to quote those 32 verses to me, and give the scriptural reference to each one?"
"In fact," God says, "one verse per year .... if you COULD recite 32 verses to me right now, with scriptural reference for each one ... for instance, 'To me, to live is Christ and to die is gain, Philippians 1:21' ... do that 32 times .... you would STILL be a pretty sorry excuse for a Christian, wouldn't you? Only one verse per year?"
God has more to say. "You were an educated, middle-class American, weren't you? Had a good-paying job? Lots of leisure time? No government oppression? Nobody in your part of the world was imprisoning Christians or confiscating Bibles? Nobody got burned at the stake? You were pretty healthy, weren't you, right up until the plane crash?"
"All true, Lord."
"And as I remember, you always had time for football games on TV, and golf at the country club. Vacations with your family. In other words, you had plenty of TIME to read your Bible ... I'm beginning to think that FOUR Bible verses per year should be your minimum. So go ahead. Quote the Bible to me. You know ... that book that you respected so much that you stood up when the pastor read from it. Give me your 128 verses. More, if you got 'em."