"You, my brother, have but a faint sense of what you have been doing. You have been standing directly in the way of your sisters’ advancement in the divine life. They, more especially F, have been entangled with the bewitching, satanic wiles of spiritualism, and if she rids herself of this unholy slime of Satan, which has perverted her sense of eternal things, she will have to make a mighty effort. It will be but a hairbreadth escape. You have been blinded, deceived, and enchanted yourself. You do not see yourself. You are all very weak, when you might be strong in the precious, saving truth, strengthened, established, and settled upon the Rock Christ Jesus. I feel deeply. I tremble for you. I see temptations on every hand, and you with so little power to resist them. 3T 40.1"
"In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them."
The EGW passage speaks of being blinded and deceived, which aligns with the concept in 2 Corinthians 4:4 of the god of this world blinding the minds of unbelievers. While not a direct quote, the theme of spiritual blindness is present in both.
Brother E, I was shown that you are infatuated; you are deceived as to your motives and the real purposes of your heart. I saw you in the society of Brother G's daughter. She has never yielded her heart to Christ. I was shown her affected and convicted. But your course was not of that character to deepen conviction, or to give her the impression that there was special importance attached to these matters. You profess to hold sacred the salvation of the soul, and the present truth. She does not respect the Sabbath from principle. She loves the vanity of the world and enjoys the pride and amusements of life. But you have been departing so gradually from God, and from the light, that you do not see the separation which the truth necessarily brings between those who love God and those who are lovers of pleasure more than lovers of God. I saw that you were attracted to her society. Religious meetings and sacred duties were of minor importance, while the presence of a mere child, who has no …
"Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?"
EGW's counsel against associating with someone who doesn't respect the Sabbath and loves worldly pleasures directly reflects the principle of not being unequally yoked with unbelievers, as stated in 2 Corinthians 6:14.