"Early in the history of the church the mystery of iniquity foretold by the apostle Paul began its baleful work; and as the false teachers concerning whom Peter had warned the believers, urged their heresies, many were ensnared by false doctrines. Some faltered under trial and were tempted to give up the faith. At the time when John was given this revelation, many had lost their first love of gospel truth. But in His mercy God did not leave the church to continue in a backslidden state. In a message of infinite tenderness He revealed His love for them and His desire that they should make sure work for eternity. “Remember,” He pleaded, “from whence thou art fallen, and repent, and do the first works.” Verse 5 . AA 587.1"
"For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way."
The EGW passage directly references the 'mystery of iniquity' and cites Revelation 2:5, making a clear connection to 2 Thessalonians 2:7 and Revelation.
"The church was defective and in need of stern reproof and chastisement, and John was inspired to record messages of warning and reproof and entreaty to those who, losing sight of the fundamental principles of the gospel, should imperil their hope of salvation. But always the words of rebuke that God finds it necessary to send are spoken in tender love and with the promise of peace to every penitent believer. “Behold, I stand at the door, and knock,” the Lord declares; “if any man hear My voice, and open the door, I will come in to him, and will sup with him, and he with Me.” Revelation 3:20 . AA 587.2"
"Behold, I stand at the door, and knock: if any man hear my voice, and open the door, I will come in to him, and will sup with him, and he with me."
Ellen White directly references Revelation 3:20 in this passage.
"And for those who in the midst of conflict should maintain their faith in God, the prophet was given the words of commendation and promise: “I know thy works: behold, I have set before thee an open door, and no man can shut it: for thou hast a little strength, and hast kept My word, and hast not denied My name.” “Because thou hast kept the word of My patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth.” The believers were admonished: “Be watchful, and strengthen the things which remain, that are ready to die.” “Behold, I come quickly: hold that fast which thou hast, that no man take thy crown.” Verses 8, 10, 2, 11 . AA 587.3"
"I know thy works: behold, I have set before thee an open door, and no man can shut it: for thou hast a little strength, and hast kept my word, and hast not denied my name."
The EGW passage directly quotes Revelation 3:8 and other verses from Revelation, making it a clear explicit allusion.