"The covenant of “life and peace” God had made with the sons of Levi—the covenant which, if kept, would have brought untold blessing—the Lord now offered to renew with those who once had been spiritual leaders, but who through transgression had become “contemptible and base before all the people.” Malachi 2:5, 9 . PK 706.1 Solemnly evildoers were warned of the day of judgment to come and of Jehovah's purpose to visit with swift destruction every transgressor. Yet none were left without hope; Malachi's prophecies of judgment were accompanied by invitations to the impenitent to make their peace with God. “Return unto Me,” the Lord urged; “and I will return unto you.” Malachi 3:7 . PK 706.2"
"My covenant was with him of life and peace; and I gave them to him for the fear wherewith he feared me, and was afraid before my name."
EGW directly quotes Malachi 2:5.
"Therefore have I also made you contemptible and base before all the people, according as ye have not kept my ways, but have been partial in the law."
EGW directly quotes Malachi 2:9.
"Even from the days of your fathers ye are gone away from mine ordinances, and have not kept them. Return unto me, and I will return unto you, saith the Lord of hosts. But ye said, Wherein shall we return?"
Ellen White directly references Malachi 3:7 in this passage.
"It seems as if every heart must respond to such an invitation. The God of heaven is pleading with His erring children to return to Him, that they may again co-operate with Him in carrying forward His work in the earth. The Lord holds out His hand to take the hand of Israel and to help them to the narrow path of self-denial and self-sacrifice, to share with Him the heirship as sons of God. Will they be entreated? Will they discern their only hope? PK 706.3"
"Come now, and let us reason together, saith the Lord: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool."
Both passages emphasize God's invitation to return and be reconciled, though Isaiah 1:18 focuses on forgiveness of sins while the EGW passage focuses on cooperation and heirship.
"Now then we are ambassadors for Christ, as though God did beseech you by us: we pray you in Christ’s stead, be ye reconciled to God."
Both passages deal with God pleading with people to be reconciled to Him. The EGW passage speaks of God pleading with His erring children, while 2 Corinthians 5:20 speaks of God beseeching through ambassadors.