Topic summary
Christian Trinity

Extracted from the Wikipedia article Trinity.
Judaism
While Judaism traditionally rejects the doctrine of the Trinity, some Jewish mystical texts have expressed ideas that bear a resemblance to trinitarian concepts. For example, the Zohar (AD 1286), a foundational work of Jewish mysticism, states that "God is they, and they are it." This passage has been interpreted by some as referencing a kind of "kabbalistic trinity," describing "three hidden lights" within "the root of all roots"—a unified essence and origin. The parallels between these mystical notions and Christian trinitarianism were striking enough that some medieval Jewish thinkers suggested the Christian Trinity may have arisen from a misinterpretation of Kabbalistic teachings. However, some recent Jewish scholars instead view the Zohar as being influenced by Christian trinitarianism. Nevertheless, some later Jewish Aristotelians borrowed from the trinitarian analogies of Augustine of Hippo, making the claim that God is a thinker, thinking, and thought itself.