That's one way we can, yes. The shadow is some aspect of ourselves we see as undesirable that we have denied, repressed, or otherwise disowned rather than make peace with and integrate in healthy ways into ourselves. It can influence us at the subconscious level. Plus there are other areas in our lives as well that works against our own better judgments, such as a lack of discipline, a lack of faith in ourselves, critical self-judgments, and all manner of things which we give into which work against us that aren't operating at the subconscious level. As the Apostle Paul cried, 'That which I would do, that thing I do not; that which I would not do, that thing I do! Oh wretched man that I am, who shall save me?'
So that kind of comes to your questions of can we go against God's will, and then 'why pray'. You can understand God in a way as your own denied Self. In a sort of transcendent, vertical direction, God is the unrealized, unrecognized, unaccepted divine aspect of our own being, which like the shadow is a part of ourselves for whatever reason we feel disposed to disown. But instead of being seen as darkness in us we wish to hide away from out of fear it will devour and destroy us (which will appear as the devil to us), it is the other end of the spectrum which is a Light in ourselves we cannot bear to look into for fear it will consume us. On the one hand you have a denial of our self, and the other a denial of the Self. And there we live in the middle disowning the darkness and disowning the Light, trying to keep from drowning as we fight against the currents of the stream we spend our lives in mastering staying alive by treading water, barely keeping our noses above the surface to breath in air. Is it any wonder the great traditions see clinging the source of suffering?
So yes, we go against God's will anytime we act within our 'lower' self with disregard to the 'higher', or the divine Self within. We 'sin' against God as we act in denial of that Light in ourselves. We fall short of that mark, as it were, of that Light in ourselves. Like learning how to integrate the shadow through a practice of self-acceptance, the result of which leads to a healthy mind and body in our daily lives, we also learn to accept the Light through a practice of Self-acceptance as it were, getting to know "God" and integrating that Light into our being in a path of transformation. We overcome the world, so to speak, by accepting the Self into the self. We now don't merely tread water in that stream barely keeping our noses above the surface in order to breathe living giving air, we stand up in it, walk around, feeling that air on our whole bodies as we walk across its surface. We are 'in the world, but not of the world' would be another metaphoric way to express this.
So why pray? At its most basic it is 'looking upward'. It is looking to God, or that Light "above" as it were. It points the mind and body and spirit to what is seen as outside itself presently, hopefully opening up the inner heart of the person to that Light than shines within. There are obviously various stages of this practice, where at its most fundamental is approached like a child asking his parent for a gift. The child is obviously unaware of any of the deeper realities in himself yet, as they have yet to develop as he matures. God is envisioned as a magical being outside himself he must interact with in order to have good things come to him in his life. But as the child matures into an adult he begins to see what God was to him 'outside' himself, actually is and always has been present within himself. God doesn't live in the sky, like Santa at the North Pole, but has never been anywhere but ever-within, fully, always, already present, nearer than our own breath.
At this point, prayer takes on the flavor of communion of spirit with Spirit. It is no longer asking for a gift from above, but rather a receiving and realization of Spirit. It becomes an immersion in God and an exchange of Light, from above and from within. In this practice it opens us to God, both within and without. It is like in psychotherapy where one learns to integrate the shadow. In meditation, in this sort of contemplative prayer one learns to integrate the Divine, which like the shadow we deny as our true Self, our true Identity. Prayer in this sense is coming to know your Self. You experience God as nearer to you than your breath, to such a point as you become absolutely One with this in yourself. You awaken to your Self. My breath is God's breath. God's breath is my breath.
So simply put, prayer is an act of reaching for the Light, and it takes on many stages of practice and flavors depending on where someone is starting from on their path of a spiritual awakening. Or it can be nothing but a simply social ritual, with no actual seeking, that too.
