It's a tricky phrase, and translations render it differently. The NRSV translates it: "Human wrath serves only to praise you." The NLT: "Human defiance only enhances your glory." The NET judges that the wrath in view is God's wrath: "your angry judgment upon men will bring you praise."
I think the general idea is that human wrath becomes, in the end, something that God overcomes and thereby demonstrates His glory. The wrath itself isn't praising God, but God overcoming wrath will lead to praise.
This line from Psalm 76 echoes back to Psalm 2:
Why do the nations rage
and the peoples plot in vain?The kings of the earth set themselves,
and the rulers take counsel together,
against the Lord and against his Anointed.
The kings and nations of the earth are wrathful, angry, and raging. They resist God's just and righteous rule. But God, in the end, will establish his kingdom. As Psalm 76 envisions:
From heaven you pronounced judgment.
The earth feared and grew quiet
when God rose up to judge
and to save all the lowly of the earth.
The nations of the world are especially wrathful right now. The kings and rulers of the earth take counsel against the Lord and his Anointed. Consequently, we're still waiting for the wrath of man to turn into praise. The vision of Psalm 76 comes to us as an eschatological hope. And that hope is our resistance.
