The spiritual is at the core of everything, and is therefore infinitely permeable to prayer. We are related to every other self in the universe. In such a world, we no longer know the limits of the possible. Therefore we pray for whatever we feel is right, and leave the outcome to God. We live in expectation of miracles in a world reenchanted with wonder.
Intercessory prayer is a perfectly rational response to such a universe.
It changes us and it canchange the world by changing what is possible to God. We are commanded to command God. Praying is rattling God's cage and waking God up and setting God free and giving this famished God water and this starving God food and cutting the ropes off God's hands and the manacles off God's feet and washing the caked sweat from God's eyes and then watching God swell with life and vitality and energy and following God wherever God goes. We have long accepted that God is limited by our freedom. What God is able to do in the world is hindered, to a considerable extent, by the rebelliousness, resistance, and self-interest of the Powers exercising their freedom under God.