Origen is the first Christian who proposed a systematically trinitarian theology of love. This has largely escaped the attention of theologians and remains underexplored. One notable consequence is that this has severely limited our appreciation of Origen as a significant interlocutor for contemporary theology since the Trinity as love is arguably the most significant theme that shaped the development of modern Trinitarian theology in the twentieth century. This essay addresses this lacuna by offering a reconstruction of Origen’s Trinitarian theology of love. What will emerge is a grammar of love that sets out the meaning of the term with reference to all three divine hypostases, Father, Son, and Holy Spirit. Furthermore, Origen’s Trinitarian understanding of love is bound up with his vision of human deification understood as incorporation into the Triune fellowship of love. At the heart of Origen’s approach is a crucial distinction from 1 John: the Father as he agapē (1 John 4:8) and the Son as he agapē ek tou theou (1 John 4:7). This distinction captures Origen’s understanding of the Father-Son relation and emerges from close attention to the Johannine language of sonship as ek tou theou. This central observation urges a reassessment of subordinationism as a characterisation of Origen’s Trinitarian thought. I argue that it is more appropriate instead to speak of Origen’s Johannine theology of sonship.