"The Lord bestowed upon these men whom the world admires, priceless intellectual gifts; He endowed them with master minds; but they did not use their powers to the glory of God. They separated themselves from Him, as did Satan; but while they separated themselves from Him, they still retained many of the precious gems of thought which He had given them. These they have placed in a framework of error, to give luster to their own human sentiments, to make attractive the utterances inspired by the prince of evil. CT 26.1"
"How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations! For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north: I will ascend above the heights of the clouds; I will be like the most High. Yet thou shalt be brought down to hell, to the sides of the pit."
The EGW passage explicitly references Satan's separation from God and the retention of his original gifts, which directly parallels the fall of Lucifer described in Isaiah 14:12-15. The thematic connection is strong and intentional.
"But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more."
The EGW passage discusses the responsibility that comes with intellectual gifts, echoing the principle in Luke 12:48 that those given much will be required to give much in return. However, the connection is not a direct quote or explicit allusion, so the confidence is slightly reduced.
"It is true that in the writings of pagans and infidels there are found thoughts of an elevated character, which are attractive to the mind. But there is a reason for this. Was not Satan the light bearer, the sharer of God's glory in heaven, and next to Jesus in power and majesty? In the words of Inspiration he is described as one who sealeth up the sum, “full of wisdom, and perfect in beauty.” The prophet declares, “Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire. Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.” Ezekiel 28:12, 14, 15 .... CT 26.2"
"Son of man, take up a lamentation upon the king of Tyrus, and say unto him, Thus saith the Lord God; Thou sealest up the sum, full of wisdom, and perfect in beauty. Thou hast been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created. Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire. Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee."
The EGW passage directly quotes Ezekiel 28:12-15 and uses it to support the argument about Satan's original perfection and subsequent fall. This is a clear and undeniable explicit allusion.