The Psalm is, first of all, directed [spoken] to the choirmaster, for public singing.
Verse 1 says: "God is [our] refuge". There are repeated references that indicate that the "us", "we", in this Psalm refer to the covenant people of God (i.e. the Hebrew nation) whose God is Yahweh.
See vss. 4-7, where the "city of God"— the place where Yahweh particularly manifested His presence [Ps. 48:1-3, cf. Exod. 15:17]—is mentioned. God will help "her"; her being in juxtaposition to the "nations" and the "kingdoms" (i.e. those apart from Israel).
Note: The "God of Jacob is [our] fortress". This can only refer to the Hebrew nation's God, namely Yahweh.
So (in short): Though the nations (those peoples and kingdoms outside of the covenant people of God) rage and war against the covenant people of God, God Himself will always be a strong tower for refuge and safety. The victory will intimately be His. God, through this song, speaks to the hearts of His covenant people to comfort them and strengthen their faith.
This OT Psalm is fulfilled in Jesus the Messiah and the New Covenant he established through His life and death and resurrection in fulfillment of the OT prophesies. All those “in Christ” are the true covenant people of God; both Jews and Gentile believers. (Gal. 3:26-29)