1 Cor. 15:22. - For as in Adam all die even so in Christ all shall be made alive

We are either in Christ or in Adam. All of us are born with Adam's nature, and are therefore liable to the death which that nature incurred. In contrast if we are in Christ what flows down to us is everything that comes from Christ.

Joshua3:14-16 So it was, when the people set out from their camp to cross over the Jordan, with the priests bearing the ark of the covenant before the people, and as those who bore the ark came to the Jordan, and the feet of the priests who bore the ark dipped in the edge of the water (for the Jordan overflows all its banks during the whole time of harvest), that the waters which came down from upstream stood still, and rose in a heap very far away at Adam, the city that is beside Zaretan. So the waters that went down into the Sea of the Arabah, the Salt Sea, failed, and were cut off; and the people crossed over opposite Jericho.

Where Jesus was baptised by John was between Adam and the final destination of the Jordan the Salt or Dead Sea. Jesus was anointed to be the one who would cut off the flow from Adam. The lamb of God that would take away the sins of the world by taking the punishment that we deserve by being crucified and dying in our place.