Notes from Matthew 26:40, 41
Jesus used Peter's drowsiness to warn him about the kinds of temptation he would soon face. The way to overcome temptation is to keep alert and pray. Keeping alert means being aware of the possibilities of temptation, sensitive to the subtleties, and spiritually equipped to fight it. Because temptation strikes where we are most vulnerable, we can't resist it alone. Prayer is essential because God's strength can shore up our defenses and defeat Satan's power.
Notes from Luke 4:1-13
Knowing and obeying God's Word is an effective weapon against temptation, the only offensive weapon provided in the Christian's "armor" (Ephesians 6:17). Jesus used Scripture to counter Satan's attacks, and so should we. But to use it effectively, we must have faith in God's promises because Satan also knows Scripture and is adept at twisting it to suit his purposes. Obeying the Scriptures is more important than simply having a verse to quote, so read them daily and apply them to your life. Then your "sword" will always be sharp.