Origen of Alexandria, Against Celsus 1.46

The law and the prophets have been fulfilled through paradoxes like those recorded about Jesus at his baptism — the dove and the voice from heaven. I take this as a sign of the Holy Spirit who appeared then in the form of a dove, pointing to the extraordinary things Jesus did. Celsus accuses him of learning these from Egyptians and performing them, but I will not rely on these accounts alone. It is also probable, given what Jesus' apostles accomplished, that they could not have moved people hearing new words and new teachings to abandon their ancestral traditions and accept theirs — risking dangers even to death — unless they had been backed by powers and extraordinary events. Traces of that same Holy Spirit, who appeared as a dove, are still preserved among Christians: they cast out demons, perform many healings, and perceive certain future things according to the will of the Word. Even if Celsus mocks what I am about to say, or the Jewish interlocutor he introduces, it must still be said that many have come to Christianity as if against their will, some spirit suddenly turning their governing faculty from hating the Word to dying for it, and making them think they were in a trance or a dream. We have recorded many such cases; if we wrote them down after encountering and seeing them ourselves, we would only invite broad ridicule from unbelievers, who already suppose we fabricate these things just as they imagine. But God is witness to our conscience: we want to establish the divine teaching of Jesus not through false reports, but through some varied and clear manifestation. Since the Jew expresses doubt about the written account of the Holy Spirit descending in the form of a dove upon Jesus, one should say to him: 'Tell me, who is speaking in Isaiah when it says, "And now the Lord has sent me and his Spirit"?' (Isaiah 48:16). The passage is ambiguous — whether the Father and the Holy Spirit sent Jesus, or the Father sent both the Christ and the Holy Spirit. The second reading is the true one. And since the Savior was sent first, then the Holy Spirit, so that the prophet's words might be fulfilled, the fulfillment of that prophecy had to be made known to later generations as well. For this reason, Jesus' disciples recorded what took place.