"I saw that the greater the light which the people reject, the greater will be the power of deception and darkness which will come upon them. The rejection of truth leaves men captives, the subjects of Satan's deception. After the Conferences at —— and ——, the subjects of this delusion were left to still greater darkness, to enter deeper into this strong delusion, and bring upon the cause of God a stain which would not soon be wiped away. A fearful responsibility is resting upon Brother G. While professing to be a shepherd he suffered the devourer to enter the flock, and looked on while the sheep were torn and devoured. God's frown is upon him. He has not watched for souls as one who must give account. 1T 232.1"
"And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil."
Both passages directly link the rejection of light/truth with an increase in darkness/deception. The EGW passage expands on this principle, applying it to a specific situation, but the core idea is clearly derived from John 3:19.
"abounds in the heart, working in those who profess the name of Christ, it will be like a refining fire, consuming the dross and scattering the darkness. Whatever is of the spirit of Satan takes the attitude of defense, and quickly works out its own destruction. But truth will triumph. 1T 232.2"
"But who may abide the day of his coming? and who shall stand when he appeareth? for he is like a refiner’s fire, and like fullers’ soap:"
The EGW passage explicitly uses the imagery of a 'refining fire' to describe the effect of truth, which is a direct allusion to Malachi 3:2. The context of consuming dross further strengthens this connection.