Angela’s rich Christology and Trinitarian theology unfold in the context of her reflection on divine union. For Angela, union with God is a participation in the incarnation of Christ and ultimately in the Trinity itself. I argue that Angela’s understanding of Christ’s hypostatic union and the Trinitarian unity-in-distinction provides her with the theological framework to describe her own union with God. These theological concepts allow her to understand divine union as a state of profound mutuality between God and the soul in which the distinctiveness of each nature seems to become permeable. Angela’s humanity and God’s divinity share individual characteristics that would not otherwise be attributed to them. God shares in the human experiences of poverty, suffering, and contempt, while Angela’s humanity shares in the transcendent darkness of the divine. The divine shares in human passibility (while paradoxically remaining impassible); while the human being is able to share in God’s very self (theōsis). The astounding mutuality between the soul and God in Angela’s theology sometimes seems to stretch the boundaries of orthodoxy, but Angela’s understanding of divine union always maintains the distinctness of human and divine. Rooted in Chalcedonian Christology, Angela preserves God’s impassibility while allowing him to share in the suffering, poverty, and contempt of Cross. Similarly, Angela’s understanding of theōsis upholds her human distinctness even when she is immersed in the divine darkness and standing amid the Trinity.