Psalms 119:11
Your word I have hidden in my heart,
That I might not sin against You.

Remember that book report you did in high school. You can actually read the book and do a good job. Or you can skim through it and do a fair report.
Cliff notes gave a little bit of an advantage over not reading it at all.
And perhaps you could just ask the other students that read the book what I was actually about.
Which student do you think will get a better grade?
Probably the one that read the book.

There are Christians that read and know the Bible.
There are Christians that only hear God’s word when they attend church.
There are Christians that get bits and pieces of the Bible and hold only to that which they personally agree with.
There are Christians that believe they receive God’s word by osmosis.
Which one do you think will actually live according to God’s word?
Probably the one that reads The Book.

David allowed God’s word to dwell in his heart so that he would not sin against God. Only someone that hides God word in their heart can do this.
Read God’s word for yourself. Hide it in your heart!