Mind like water is one of the main metaphors utilized by GTD. I’m not so sure, however, that it’s actually a good or biblical state of mind.
Note, for example, Tim Chester’s excellent description of the Christian’s prayer life in Total Church:
Calvin however, says a “sweet and perfect repose” is not the characteristic of the spiritually advanced but simply of those whose “affairs are flowing to their liking.” “For the stains,” he continues, “the occasion that best stimulates them to call upon God is when, distressed by their own need, they are troubled by the greatest unrest, and are almost driven out of their senses, until faith opportunely comes to their relief” (Institutes 3.20.11).
Biblical spirituality is not a spirituality of silence; it is a spirituality of passionate petition. If we are engaged with the world around us, we will care about that world. We will be passionate about people’s needs, our holiness, and God’s glory. We will not be still in prayer. We will cry out for mercy with a holy violence. If we are silent, it will be because in our distress, words have failed us. This is the spirituality of the psalms—a spirituality in which all of our emotions are engaged.