Satan is preparing his deceptions that in his last campaign against the people of God, they may not understand that it is he. “And no marvel; for Satan himself is transformed into an angel of light.” ... Satan will go to the extent of his power to harass, tempt, and mislead God's people.
He who dared to face, and tempt, and taunt our Lord, and who had power to take Him in his arms and carry Him to a pinnacle of the temple, and up into an exceeding high mountain, will exercise his power to a wonderful degree upon the present generation, who are far inferior in wisdom to their Lord, and who are almost wholly ignorant of his subtlety and strength.
In a marvelous manner will he affect the bodies of those who are naturally inclined to do his bidding.54Messages to Young People, 51-52.
He will come personating Jesus Christ, working mighty miracles; and men will fall down and worship him as Jesus Christ.
We shall be commanded to worship this being, whom the world will glorify as Christ. What shall we do?—Tell them that Christ has warned us against just such a foe, who is man's worst enemy, yet who claims to be God; and that when Christ shall make His appearance, it will be with power and great glory, accompanied by ten thousand times ten thousand angels and thousands of thousands; and that when He shall come, we shall know His voice.55SDA Bible Commentary 6:1105-1106.
The time is coming when Satan will work miracles right in your sight, claiming that he is Christ; and if your feet are not firmly established upon the truth of God, then you will be led away from your foundation.56SDA Bible Commentary 7:911.
Satan is determined to keep up the warfare to the end. Coming as an angel of light, claiming to be the Christ, he will deceive the world. But his triumph will be short. No storm or tempest can move those whose feet are planted on the principles of eternal truth. They will be able to stand in this time of almost universal apostasy.57SDA Bible Commentary 6:1106. Mar 206
More than this, Christ changes the heart. He abides in your heart by faith. You are to maintain this connection with Christ by faith and the continual surrender of your will to Him; and so long as you do this, He will work in you to will and to do according to His good pleasure. So you may say, “The life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave Himself for me.” Galatians 2:20. So Jesus said to His disciples, “It is not ye that speak, but the Spirit of your Father which speaketh in you.” Matthew 10:20. Then with Christ working in you, you will manifest the same spirit and do the same good works—works of righteousness, obedience. SC 62
And no marvel; for Satan himself is transformed into an angel of light. 2 Corinthians 11:14. KJV