Hallelujah means praise the Lord. The rest of this verse describes how praising the Lord can occur. Remarkably, it says here that praise not only has value to God, but that praise also has meaning for the people who are praising. It is good for people to praise the Lord. Why that is so? The Psalm does not say, but the basis of any answer will be that people must live in a relationship with God.

In this special relationship with the Lord, it will also be good for you to praise God.