When we talk about "parting the waters" we typically think of Moses at the Red Sea leading the people out of slavery into freedom.
We may also think of Joshua at the River Jordan leading the people out of wandering into the promised land.
In a similar way when the heavens were opened at Jesus' baptism I argue that there was another kind of parting of the waters, but not one we in our 21st century mindset would necessarily be attuned to. The 1st century cosmological view was of a three tiered universe where the earth on which we live is surrounded by water, above and below. When the heavens are parted then, in fact, the heavenly waters are parted.
The significance of this is that Jesus is a kind of second Moses, leading the people to liberation, and a second Joshua, leading the people to the promised land, but instead of a lateral and temporal movement, his aim is higher and of eternal significance. Instead of settling for a short term military or political solution to the ills of his people, Jesus takes the long view and looks to bring peace and reconcilation between all peoples and God.
It is not the Messiah that the people were looking for. But in many ways Jesus exceeded their expectations. We often desire a God who descends from above, like Superman, to solve all our problems, smite the bad guys, and bless the good guys. Or we want a God who will make war on our enemies. But God's power in the Baptism of Jesus is made manifest in a dove.
Is it a bird? Is it a plane? Is it Superman? Nope, it's a bird. And not even a cool bird of prey, but a dove, a symbol of peace, a symbol of God's covenant.
And so, in our own baptisms, we are called to resist evil and fight injustice, but with a long view of reconciliation and peace.
This video is an example of the superhero image of God taken to absurd ends.