Jesus the Messiah has come in the flesh is from God; but every spirit that does not believe that the Messiah has come in the flesh is not from God, but from the False Messiah who is even now in the world.”
Hence it is evident that the term “spirit,” in their idiom, embraces the human messenger-prophet. Gabriel, who brought the revelation down to Muhammad, is the Holy Spirit, the Spirit of Truth, as the Exalted says:
“Say: The Holy Spirit has brought it down from your Lord, in truth” (al-Nahl 16:102);
“The Trustworthy Spirit has brought it down—upon your heart” (al-Shuʿarāʾ 26:193–194);
and: “Whoever is an enemy to Gabriel—surely it is he who has brought it down upon your heart by Allah’s leave” (al-Baqarah 2:97).
This Spirit was designated only with the advent of Muhammad, and the discourse he brought down is—