"We are near the close of time. I have been shown that the retributive judgments of God are already in the land. The Lord has given us warning of the events about to take place. Light is shining from His word; yet darkness covers the earth, and gross darkness the people. “When they shall say, Peace and safety; then sudden destruction cometh upon them; ... and they shall not escape.” 5T 99.3"
"For when they shall say, Peace and safety; then sudden destruction cometh upon them, as travail upon a woman with child; and they shall not escape."
EGW directly quotes 1 Thessalonians 5:3, making this a clear and explicit allusion.
It is our duty to inquire the cause of this terrible darkness, that we may shun the course by which men have brought upon themselves so great delusion. God has given the world an opportunity to learn and to obey His will. He has given them, in His word, the light of truth; He has sent them warning, counsel, and admonition; but few will obey His voice. Like the Jewish nation, the majority, even of professed Christians, pride themselves on their superior advantages, but make no returns to God for these great blessings. In infinite mercy a last warning message has been sent to the world, announcing that Christ is at the door and calling attention to God's broken law. But as the antediluvians rejected with scorn the warning of Noah, so will the pleasure lovers of today reject the message of God's faithful servants. The world pursues its unvarying round, absorbed as ever in its business and its pleasures, while the wrath of God is about to be visited on the transgressors of His law. 5T 99.4…
"Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter!"
Both passages address a reversal of values and a rejection of God's warnings. Isaiah 5:20 speaks of calling evil good and good evil, while the EGW passage describes the world rejecting God's warnings and pursuing worldly pleasures. The connection is thematic, focusing on the distortion of truth and rejection of divine guidance.