There is a strife between the forces of good and evil, between the loyal and the disloyal angels. Christ and Satan are not at an agreement, and they never will be. In every age the true church of God has engaged in decided warfare against satanic agencies. Until the controversy is ended, the struggle will go on between wicked angels and wicked people on the one side, and holy angels and true believers on the other. (CTr 28.2)

The battle that is raging will grow more fierce as the end approaches. Those who are in unity with satanic agencies are designated by the Lord as the children of darkness. There is not, and cannot be, a natural enmity between fallen angels and fallen humans. Both are evil. Through apostasy both cherish evil sentiments. Wicked angels and wicked people are leagued in a desperate confederacy against the good. Satan knew that if he could induce the human race, as he had induced angels, to unite with him in his rebellion, he would have a strong force with which to carry on his rebellion. (CTr 28.3)

In the hosts of evil there is jarring and discord, but they are all firm allies in fighting against heaven. Their one aim is to disparage God, and their great numbers lead them to entertain the hope that they will be able to dethrone Omnipotence. (CTr 28.4)

When Adam and Eve were placed in the Garden of Eden, they were innocent and sinless, in perfect harmony with God. Enmity had no natural existence in their hearts. But when they transgressed, their nature was no longer sinless. They became evil, for they had placed themselves on the side of the fallen foe, doing the very things that God specified they should not do. Had there been no interference on the part of God, fallen humans would have formed a firm alliance with Satan against heaven. But when the words were spoken, “I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel,” Genesis 3:15. Satan knew that although he had succeeded in making human beings sin, although he had led them to believe his lie and to question God, although he had succeeded in depraving human nature, some arrangement had been made whereby the beings who had fallen would be placed on vantage ground, their nature renewed in godliness. He saw that his actions in tempting them would react upon himself, and that he would be placed where he could not become conqueror.... (CTr 28.5)