Rev 22:1-7 / Luke 21:34-36
Before we jump into a swimming pool, it would be wise to just dip our foot into the water to feel the temperature of the water.
This is what it probably means by "to test the waters". We won't want to dive in without testing the waters first.
But when we decide to dive in, then it is certainly not a question of testing the waters anymore. If we dive in, it is because we want to do something in the water, be it for swimming or whatever.
The 1st reading mentioned about the river of life, rising from the throne of God and of the Lamb, and flowing crystal-clear down the middle of the city street.
And on either side of the river were the trees of life, which bear twelve crops of fruit a year, one in each month, and the leaves of which are the cure of the pagans.
We would certainly want to dive into that river, because it is the river of life. But we have actually already dived into that river.
By our baptism into Christ, we have be immersed in the waters of life, the waters that flow from the river of life that has its source in God.
But as Jesus said in the gospel, if we don't watch ourselves, then our hearts will be coarsened with debauchery and drunkenness and the cares of the world will drown us.
Then even in the river of life, we end up like flotsam and jetsam or some floating rubbish.
Let us remember that when we dive into the waters, it is not to test the waters. We dive into the waters to make waves, waves that will wash away our sins and the sins of the world.
It is either we make waves on the world, or the waves of the world will drown us.