1 Peter 5:8

Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour:

The Review and Herald, January 11, 1887

The days are fast approaching when there will be great perplexity and confusion. Satan, clothed in angel robes, will deceive, if possible, the very elect. There will be gods many and lords many. Every wind of doctrine will be blowing.

Testimonies for the Church, Vol. 5, p. 295

Satan hopes to involve the remnant people of God in the general ruin that is coming upon the earth. As the coming of Christ draws nigh, he will be more determined and decisive in his efforts to overthrow them.

The Signs of the Times, April 20, 1876

Satan is at work in secrecy and darkness. Cunningly he draws away the followers of Christ from the cross, and brings them into self-indulgence and wickedness.

Satan is opposed to everything that will strengthen the cause of Christ and weaken his own power. He is diligently laying plans to undermine the work of God. He never rests for a moment when he sees that the right is gaining the ascendency. He has legions of evil angels that he sends to every point where light from Heaven is shining upon the people. Here he stations his pickets to seize every unguarded man, woman, or child, and pass them over to his service.

Manuscript Releases, Vol. 12, p. 201

Satan's purpose is, through his devices, to make of none effect the testimonies of the Spirit of God. If he can lead the minds of the people of God to see things in a perverted light, they will lose confidence in the messages God sends through His servants; then he can the more readily deceive, and not be detected.

Ibid., Vol. 8, p. 399

Satan will use every opportunity to seduce men from their allegiance to God. He and the angels who fell with him will appear on the earth as men, seeking to deceive. God's angels also will appear as men, and will use every means in their power to defeat the purposes of the enemy.

Selected Messages, Book 3, pp. 410-411

I have been shown that evil angels in the form of believers will work in our ranks to bring in a strong spirit of unbelief. These powers of evil will assemble in our meetings, not to receive a blessing, but to counterwork the influences of the Spirit of God.... In this time evil angels in the form of men will talk with those who know the truth. They will misinterpret and misconstrue the statements of the messengers of God.

Have Seventh-day Adventists forgotten the warning given in the sixth chapter of Ephesians? We are engaged in a warfare against the hosts of darkness. Unless we follow our Leader closely, Satan will obtain the victory over us.

Manuscript Releases, Vol. 8, No. 345

There will be seducing spirits and doctrines of devils in the midst of the church, and these evil influences will increase; but hold fast the beginning of your confidence firm unto the end.

Satan and his angels will appear on this earth as men, and will mingle with those of whom God's Word says, ‘Some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils.’ (1 Timothy 4:1).

Spalding and Magan Collection (1985), p. 307

The enemy works untiringly to deceive human beings, and lead them away from God. He and his angels will in the future assume the shape of human beings, and work to make the truth of God of no effect.

Special Testimonies, Series A, No. 12, p. 9

...I must warn all our churches to beware of men who are being sent out to do the work of spies in our conferences and churches,--a work instigated by the father of falsehood and deception. Let every church-member stand true to principle. We have been told what would come, and it has come.

The Signs of the Times, April 13, 1888

Those who are used as agents of Satan have an appearance of sanctity; and nothing but the law of God, which is a discerner of the thoughts of the heart, can discover of what spirit they are, and in whose cause they are engaged; but why not employ this unfailing test in proving every man's teaching and spirit. There is no need of being deceived, for the word of God is truth, and God has promised to give to those who desire truth, the Spirit of truth, that they may be guided into all truth. Let us seek earnestly for wisdom, and divine enlightenment, that we may know the truth, and be instrumental in God's hands of rescuing men and women from the snares of the evil one.