"Terrible were the trials that were to beset the true church. Even at the time when the apostle was writing, the “mystery of iniquity” had already begun to work. The developments that were to take place in the future were to be “after the working of Satan with all power and signs and lying wonders, and with all deceivableness of unrighteousness in them that perish.” AA 266.1"
"For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way. And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming: Even him, whose coming is after the working of Satan with all power and signs and lying wonders, And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. And for this cause God shall send them strong delusion, that they should believe a lie: That they all might be damned who believed not the truth, but had pleasure in unrighteousness."
The EGW passage directly alludes to and quotes from 2 Thessalonians 2:7-12, discussing the 'mystery of iniquity' and the 'working of Satan.' The connection is strong and explicit.
"Especially solemn is the apostle's statement regarding those who should refuse to receive “the love of the truth.” “For this cause,” he declared of all who should deliberately reject the messages of truth, “God shall send them strong delusion, that they should believe a lie: that they all might be damned who believed not the truth, but had pleasure in unrighteousness.” Men cannot with impunity reject the warnings that God in mercy sends them. From those who persist in turning from these warnings, God withdraws His Spirit, leaving them to the deceptions that they love. AA 266.2"
"And for this cause God shall send them strong delusion, that they should believe a lie: That they all might be damned who believed not the truth, but had pleasure in unrighteousness."
EGW directly quotes 2 Thessalonians 2:11-12 and elaborates on its meaning.
"Thus Paul outlined the baleful work of that power of evil which was to continue through long centuries of darkness and persecution before the second coming of Christ. The Thessalonian believers had hoped for immediate deliverance; now they were admonished to take up bravely and in the fear of God the work before them. The apostle charged them not to neglect their duties or resign themselves to idle waiting. After their glowing anticipations of immediate deliverance the round of daily life and the opposition that they must meet would appear doubly forbidding. He therefore exhorted them to steadfastness in the faith: AA 266.3"
"But ye, brethren, be not weary in well doing."
The EGW passage discusses Paul's admonishment to the Thessalonians to continue working and not be idle, which aligns with the principle of not being weary in well-doing found in 2 Thessalonians 3:13.
"And let us not be weary in well doing: for in due season we shall reap, if we faint not."
Both passages encourage perseverance and not growing weary in doing good, especially in the face of challenges and delayed expectations.