[Daniel 10:12, 13 quoted]. By this we see that heavenly agencies have to contend with hindrances before the purpose of God is fulfilled in its time. The king of Persia was controlled by the highest of all evil angels. He refused, as did Pharaoh, to obey the word of the Lord. Gabriel declared, He withstood me twenty-one days by his representations against the Jews. But Michael came to his help, and then he remained with the kings of Persia, holding the powers in check, giving right counsel against evil counsel. Good and evil angels are taking a part in the planning of God in His earthly kingdom. It is God’s purpose to carry forward His work in correct lines, in ways that will advance His glory. But Satan is ever trying to counterwork God’s purpose. Only by humbling themselves before God can God’s servants advance His work. Never are they to depend on their own efforts or on outward display for success. SPCCSR 22.4
An Invisible Struggle.—We have before us in the Word of God instances of heavenly agencies working on the minds of kings and rulers, while at the same time satanic agencies were also at work on their minds. No human eloquence, in strongly set forth human opinions, can change the working of satanic agencies. Satan seeks continually to block the way, so that the truth shall be bound about by human devising; and those who have light and knowledge are in the greatest danger unless they constantly consecrate themselves to God, humiliating self, and realizing the peril of the times. SPCCSR 23.1
Heavenly beings are appointed to answer the prayers of those who are working unselfishly for the interests of the cause of God. The very highest angels in the heavenly courts are appointed to work out the prayers which ascend to God for the advancement of the cause of God. Each angel has his particular post of duty, which he is not permitted to leave for any other place. If he should leave, the powers of darkness would gain advantage.... SPCCSR 23.2
Day by day the conflict between good and evil is going on. Why is it that those who have had many opportunities and advantages do not realize the intensity of this work? They should be intelligent in regard to this. God is the Ruler. By His supreme power He holds in check and controls earthly potentates. Through His agencies He does the work which was ordained before the foundation of the world. SPCCSR 23.3
As a people we do not understand as we should the great conflict going on between invisible agencies, the controversy between loyal and disloyal angels. Evil angels are constantly at work, planning their line of attack, controlling as commanders, kings, and rulers, the disloyal human forces.... call upon the ministers of Christ to press home upon the understanding of all who come within the reach of their voice, the truth of the ministration of angels. Do not indulge in fanciful speculations. The written Word is our only safety. We must pray as did Daniel, that we may be guarded by heavenly intelligences. As ministering spirits angels are sent forth to minister to those who shall be heirs of salvation. Pray, my brethren, pray as you have never prayed before. We are not prepared for the Lord’s coming. We need to make thorough work for eternity.—Letter 201, 1899. Published in Bible Commentary, Vol. 1, p. 1173. SPCCSR 24.1