"Christ had told them before that these things would take place, but they did not understand Him. The scene of His sufferings was to be a fiery ordeal to His disciples, hence the necessity of watchfulness and prayer. Their faith needed to be sustained by an unseen strength as they should experience the triumph of the powers of darkness. We can have but faint conceptions of the inexpressible anguish of God's dear Son in Gethsemane, as He realized His separation from His Father in consequence of bearing man's sin. He became sin for the fallen race. The sense of the withdrawal of His Father's love pressed from His anguished soul these mournful words: “My soul is exceeding sorrowful, even unto death.” “If it be possible, let this cup pass from Me.” Then with entire submission to His Father's will, He adds: “Nevertheless not as I will, but as Thou wilt.” 2T 206.1"
"For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him."
EGW quotes Jesus' words from Gethsemane and directly references the concept of Jesus becoming sin for us, as described in 2 Corinthians 5:21.