When we think that we are good enough without drinking deeply daily from the scriptures, what does the Lord think of the matter? He calls it "vanity and unbelief" in D&C 84. In fact, he goes further than that, and claims that every individual alive at the time was not taking the scriptures seriously enough. Wow! This is one of those times when even the marvelous prophet Joseph Smith was rebuked.
The Lord's term "vanity" for our disobedience is all too perfect. Vanity is to think we are so much better than others, and in that pride to also think we are far better than we really are. It is to be puffed up with our own spiritual beauty. It is to look in the spiritual mirror and admire ourselves.
We call ourselves believing, but the Lord says that not taking his scriptures seriously enough, not only to read, but to do, is unbelief. We say we believe, but he begs to differ.
Faithful Peter was told he was not yet converted, so it is no wonder that the Lord's message to us is that we do not yet fully believe. But righteous Peter provides no excuse for our failure in this matter as the Lord has told us exactly what needs to be done.
We must cease to take lightly the Book of Mormon and the revelations god has given in the scriptures, not only to say, but to do according to that which is written.