Praise the Lord all you Gentiles! Laud Him all you peoples! For His merciful kindness is great toward us, and the truth of the Lord endures forever. Praise the Lord!
David is not shouting praises to God! He is not even shouting to anyone who may be in earshot! The Gentiles are the foreign nations. People and people groups outside of his dwelling place, outside of his community where his own people would hear him!
David did not ask that the nations be saved. He commanded them to praise the Lord, praise his God, for the merciful kindness shown to all humanity, declaring the truth of the Lord forevermore.
Praise Him all you (coworkers of your place of employment)! Laud Him all you employees who follow other gods! For His merciful kindness towards you is great and He is eternal Truth, Creator of Heaven and Earth!)
Praise the Lord KANAWHA and Putnam Counties! Praise the Lord Saint Albans! Praise the Lord!