His word is light, that if any of us might believe in him, that they might be made to be born as a son of light. Therefore the Savior said: "As long as you have the light, believe in the light, that you be born sons of the light." For as this sensible light is for the body, thus noetically is the word of God for souls. And as there is the darkness at night, thus is there delusion in ignorant souls. Because of this, the blessed David writes of this, saying: "They did not know, nor did they perceive that they were walking in darkness..."