Psalm 146 is a poem that is written to help us remember that God is really powerful and He is in charge of everything. It tells us to always praise God because He is the one who made the world and keeps everything running.
It says that we should never rely on people or things to make us happy or safe because they can't always be there for us, but God will always take care of us. It also reminds us that God cares about people who are treated unfairly and will make everything fair in the end.
The poem ends by saying that we should always praise God and trust Him because He is the best and He will always be with us no matter what.