It frankly does not make sense to occasionally 'fill up' with water, with long periods of dehydration in between. The same thing is true spiritually. Spiritual thirst is a need for living water. A constant flow of living water is far superior to sporadic sipping.
Satan does not have a body, and his eternal progress has been halted. Just as water flowing in a riverbed is stopped by a dam, so the adversary's eternal progress is thwarted because he does not have a physical body.
Baptism by water leads to the authorized opportunity for the constant companionship of the third member of the Godhead.
