This is as close as I get to a spiritual activity. It is also emotional, physical, and intellectual. It is something that you do with your whole body and mind. With your energy and your alpha waves. With your compassion, your creativity, and your strength.
You are offering them a culture. Your personal cultute. Your version of reality. Your way of life. It had better be a good way of life. So getting a saddle on a colt reaches deep into your life. The young horse will question you in their wordless way, and you must have something to say for yourself, for your species, for the order of the world.
They come to this willingly. They give you the benefit of the doubt. That is the miracle of horses.