What’s it matter? Why is this important? Who cares about the theonomous self? Because it ought to effect how we think about and execute our liturgies, prayer, songs, and discipleship.
The theonomous self could be seen to align more with heteronomous self, the self which is imposed, legislated, or given by anOther, as a Law. And surely this is true, to an extent. But to be distinguished from merely being the Law of another, the theonomous self must be non-coercively received, it must be without violence or alienation (if that is possible). The emergence of this theonomous self is glimpsed in the OT shift from the Law to Wisdom, from outer to inner piety. But this is not an interior autonomy, free from exterior forces, but the cultivation of virtue and character guided by wisdom. Or rather, it is the shift from exterior Law to the interior of Love, which is always flowing again toward anOther.
The autonomous self ends/begins in a narcissistic loop of desire, disfiguring reality according to it own twisted logic/Law; while the heteronomous self is disfigured by another’s desire, caught in the web of a Law beyond itself, both giving life to alienation and despair. But the theonomous self is received from anOther who would rather give his life than take ours, who draws us into the eternal self-giving of perichoretic love between Father, Son, and Spirit.
Therefore, as we enter into times of prayer, discipleship, singing, and liturgy, we must be aware of the dual pull of auto-/heteronomy at work in the lives of all those following Christ. We must work tirelessly to overcome the dialectic of other and same, in the Trinitarian logic of Christian worship.