"To prepare a people to stand in the day of God, a great work of reform was to be accomplished. God saw that many of His professed people were not building for eternity, and in His mercy He was about to send a message of warning to arouse them from their stupor and lead them to make ready for the coming of the Lord. GC 311.2"
"Therefore thus will I do unto thee, O Israel: and because I will do this unto thee, prepare to meet thy God, O Israel."
The EGW passage directly echoes the sentiment of Amos 4:12, which is a call to prepare to meet God. The idea of preparing a people to stand in the day of God is a clear application of the principle found in Amos.
"Therefore let us not sleep, as do others; but let us watch and be sober."
Both passages emphasize the need for vigilance and preparedness in anticipation of a significant event (the coming of the Lord/the day of God). The call to awaken from spiritual slumber is a clear thematic parallel.
"heavenly beings and immediately followed by the coming of the Son of man to reap “the harvest of the earth.” The first of these warnings announces the approaching judgment. The prophet beheld an angel flying “in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people, saying with a loud voice, Fear God, and give glory to Him; for the hour of His judgment is come: and worship Him that made heaven, and earth, and the sea, and the fountains of waters.” Revelation 14:6, 7 . GC 311.3"
"And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people,"
The EGW passage directly quotes Revelation 14:6, making it an explicit allusion.
"Saying with a loud voice, Fear God, and give glory to him; for the hour of his judgment is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters."
The EGW passage directly quotes Revelation 14:7, making it an explicit allusion.
"And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come."
Both passages relate to the preaching of the gospel to all nations before the end. While EGW is focused on the first angel's message, which includes preaching to all nations, Matthew 24:14 speaks of the gospel being preached as a sign of the end. There is a thematic parallel.