From Psalm 146, this is known as a Hallel psalm (begins and ends with the Hebrew word hallelujah). It is a call to worship him as Creator and Redeemer because he is the truly worthy one.

Praise the Lord, O my soul! 
I will praise the Lord as long as I live. 
I will sing praises to my God while I have my being. 
Put not your trust in princes, 
In whom there is no salvation. 
When his breath departs, he returns to the earth.
On that very day, his plans perish. 
But blessed is he whose help is the God of Israel,
Whose hope is in the Lord his God, 
Who made heaven and earth, 
The seas, and all that is in them, 
Who keeps faith forever, 
Who executes justice for the oppressed,
Who gives food to the hungry. 
The Lord sets the prisoners free. 
The Lord opens the eyes of the blind. 
The Lord lifts up those who are bowed down.
The Lord loves the righteous. 
The Lord watches over the sojourners. 
He upholds the widow and the fatherless, 
But the way of the wicked he brings to 
ruin. The Lord will reign forever. 
Your God, O Zion, will rule to all generations.
Praise the Lord!