Psalm 91 is so Important that Lucifer Quoted it.....

For He shall give his angels charge over thee, 

to keep thee in all thy ways. 

Psalm 91:11

And he brought Him to Jerusalem, and set Him on a pinnacle of the temple, and said unto Him, If Thou be the Son of God, cast Thyself down from hence: For it is written, He shall give His angels charge over thee, to keep thee:
Luke 4:9,10

***So Lucifer does study the Scriptures....