God is spirit, and in being spirit and Creator causes change and movement physically through spiritual means, planting the seeds of his desired trees, flowers, and fruit, within the invisible yet created world.
Spiritual seeds and acts of God, blossom physically through time, patience, cultivation, and through prayer, and through the strength and intercession of angels and heavenly beings.
Though establishing a structure, an act, anything for that matter, in the visible created world, fear lest there be no spiritual existence or substance to substantialize and keep it.