Psalm 48 was written by the sons of Korah as well as other psalms that we have already named before. This psalm explains the greatness of God and it shows the joy of exalting God with the one who writes, so possibly this is a Psalm of joy dedicated to God.
The people of Israel, the sons of Korah, had plenty of reasons to worship God and give Him praise. We also have many reasons to worship God, for certainly God has been good to us, from that moment that gave us salvation, plus everything He does for us on a day-to-day basis. We glorify God for His greatness.