Sing to the Lord a new song,
for he has done marvelous things;
his right hand and his holy arm
have worked salvation for him.
The Lord has made his salvation known
and revealed his righteousness to the nations.
When you read the Old Testament, you’ll read stories of God’s salvation in terms of overcoming the enemy by acts of power, sometimes through God’s people, but other times not. In fact the greatest act of redemption we find there is the Exodus, which while includes the Passover and is primarily seen as the parting of the Red Sea for God’s people to cross, after which it fell back, engulfing those intent on bringing God’s people back into bondage.
When those of that time read Psalm 98, they surely thought of that act in Exodus, the Exodus: God’s deliverance of his people from slavery. So they would not have been prepared for God’s ultimate act of salvation and redemption.
We find that in Jesus in the unimaginable way of the cross. That is where the last enemies of God are completely defeated, someday to be forever vanquished. That is where God makes his salvation known, and reveals his righteousness to the nations. The cross of Christ. His death for the world, followed by the verification of that in his resurrection.
That is the greatest act of God’s salvation. In and through Jesus.