Psalm 9:1-2

I will give thanks and praise the Lord, with all my heart; I will tell aloud all Your wonders and marvelous deeds. I will rejoice and exult in you; I will sing praise to your name, O Most High. 

Praise helps us focus on all the good that God has done in our lives. When we praise, we turn our focus off the problem and onto the solution to the problem. We express our faith in God in praise as we lift our voices and remind the devil that God is in control.