The law of God existed before man was created. The angels were governed by it. Satan fell because he transgressed the principles of God’s government. After Adam and Eve were created, God made known to them His law. It was not then written, but was rehearsed to them by Jehovah…. {CIHS 30.1}
After Adam’s sin and fall, nothing was taken from the law of God. The principles of the Ten Commandments existed before the fall, and were of a character suited to the condition of a holy order of beings.5 {CIHS 30.2}
The principles were more explicitly stated to man after the fall, and worded to meet the case of fallen intelligences. This was necessary in consequence of the minds of men being blinded by transgression.6 {CIHS 30.3}
But though fallen man could no longer talk directly with God, yet our loving heavenly Father has ever maintained communication with the human family. Through the ministry of holy angels, He has provided for men and women protection from the influences of evil, and help to live in accordance with His will. And through the agency of His Holy Spirit, God has spoken to the hearts of men, and has made it possible for even the most sinful and ignorant to find the way that leads to right-doing and to eternal life. {CET 237.2}
God has also spoken to the fallen race through chosen human agencies, to whom He has communicated a knowledge of His purpose in visions and dreams. These messengers of His will, have been known as holy men, or prophets, set apart by the Lord Himself for the special work of receiving and communicating truth from heaven to mankind. “If there be a prophet among you,” God declares, “I the Lord will make Myself known unto him in a vision, and will speak unto him in a dream.” Numbers 12:6. {CET 237.3}