In Psalm 76, “Salem” is a shortened form of “Jerusalem” (cf. Genesis 14:18).
The statement of the Psalm is that God is known by His people, particularly the people of Jerusalem.
How do they know God?
The bodies of their enemies sleep in the hillsides around Jerusalem, a lasting testimony to the presence of God, his supremacy over all contestants whether mortal or divine, and his uncompromising and incomparable favor toward His own people.
The psalm has three parts: Verses 1-5 recount what God has done in favoring Jerusalem. Verses 7-10 exalt God. Verses 11-12 call on worshipers to honor the one to be respected above all others.
In modern terms, the psalm pictures God’s people living in a protected city covered by an impenetrable dome which is the Lord. This is the city where the God of the earth dwells.
There is a message here for the Church. We are the great city of God. We should live in such a way of faith that the world recognizes the greatness of our God and comes to worship Him.