Reason requires the infallibility of the Prophets, upon them all be peace, because: As already explained, the Prophets came to convey to people the Message of God. If we liken this Message or the Divine Revelation to light or pure water, as the Qur’an itself does (al-Ra’d, 13. 17; al-Nur, 24.35), it is absolutely necessary and indispensable to the nature of the Revelation that both the Archangel Gabriel who brought the Revelation, and the Prophet himself who conveyed it to people, should be absolutely pure. Otherwise, that Divine light, the Revelation, would have been extinguished or dimmed, or that ‘pure water’ polluted.