The Power of Praise

I will praise You, LORD, with all my heart;
I will tell of all the marvelous things You have done. (Psalm 9:1)
I will be filled with joy because of You.
I will sing praises to Your name, O Most High. (Psalm 9:2)
I will praise the LORD at all times.
I will constantly speak His praises. (Psalm 34:1)
I will boast only in the LORD;
let all who are helpless take heart. (Psalm 34:2)
Come, let us tell of the LORD's greatness;
let us exalt His name together. (Psalm 34:3)

In 2 Chronicles 20:21-24, King Jehoshaphat appointed singers to walk ahead of their army to war against the armies of Moab, Ammon and Mount Seir, and they sang:

"Give thanks to the LORD;
     His faithful love endures forever!"

The LORD had given them victory over their enemies and not a single one of the enemy had escaped.

Quoting Kenneth and Gloria Copeland's book "One Word from God can Change Your Life":

"Praise will cause Satan and his forces to turn back, fall and perish at your presence."