In The Church of Jesus Christ of Latter-day Saints, we believe we were those morning stars and sons of God who shouted for joy because God was creating an earth where we could take on a body just as God has and that we learn good and evil and become more like God. We understood that it was a temporary world and that we would experience evil and also die. But we also understood that Jesus would be our Savior and that we could repent of our sins and find forgiveness through Him. We also understood that we would all be resurrected and become immortal in bodies of flesh and bones just as our Father in Heaven is. We knew Jesus would come and show us the way to salvation and eternal life. Our joy was in the opportunity to become more like our Father in Heaven and our Lord Jesus Christ. This is why Jesus commanded us to:
Matthew 5:48
48 Be ye therefore perfect, even as your Father which is in heaven is perfect.
This is why Jesus taught that we can become one even as He is one with the Father.
John 17:20-23
20 Neither pray I for these alone, but for them also which shall believe on me through their word;
21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.
22 And the glory which thou gavest me I have given them; that they may be one, even as we are one:
23 I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me.
We rejoiced and shouted for joy to see that we were to be given the opportunity to become like Our Father and our Savior. We rejoiced that we could have an immortal body of flesh and bones and gain eternal joy and happiness just as our Father in Heaven had.
Some of the premortal spirits of God followed after Lucifer and came out in open rebellion against God and were denied this great opportunity and were cast out of heaven. They became the devil and his angels. They were denied the opportunity to ever receive a body of flesh and bones and will remain only spirits for all eternity. We all here on earth who have bodies fought on the side of God our Father and our Lord Jesus Christ in the war in heaven. We fought against Lucifer and those who sided with him before they were cast out of heaven and into the earth. This occurred before we came to this earth.
Revelation 12:7-11
7 And there was war in heaven:
Michael and his angels fought against the dragon; and the dragon fought and his angels,
8 And prevailed not; neither was their place found any more in heaven.
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
10 And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of
our brethren is cast down, which accused
them before our God day and night.
11 And
they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
Notice in verse 11 that they who fought against Satan and his angels in the war in heaven came to earth and needed the blood of the Lamb to overcome him and that they need a testimony of God and were subject to death. It was we who have come this earth and received bodies that fought against Lucifer and his angels in the war in heaven. We were the angels of the archangel Michael. This mortal earth life is only temporary but it is so critical to our eternal progession that we rejoiced at the chance to come and progress. Again we believe that we were those morning stars and sons of God who shouted for joy.
Before Lucifer rebelled against God and started a war in heaven, he was know as a morning star or son of the morning.
Isaiah 14:12-17
12 How art thou fallen from heaven,
O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!
13 For thou hast said in thine heart,
I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:
14 I will ascend above the heights of the clouds; I will be like the most High.
15 Yet thou shalt be brought down to hell, to the sides of the pit.
16 They that see thee shall narrowly look upon thee, and consider thee, saying,
Is this the man that made the earth to tremble, that did shake kingdoms;
17 That made the world as a wilderness, and destroyed the cities thereof; that opened not the house of his prisoners?
Notice that Lucifer is a man. All angels are also mankind. Notice that in Daniel 9:21 that Daniel recognizes that the angel Gabriel is a man.
Daniel 9:21
21 Yea, whiles I was speaking in prayer, even
the man Gabriel, whom I had seen in the vision at the beginning, being caused to fly swiftly, touched me about the time of the evening oblation.
Also the angels of Genesis 19 who visited Lot and his family are often referred to as men in that chapter. Basically we believe that angels are either the premortal spirits of man or mortal mankind or translated man or post mortal spirits of man or post mortal resurrected man. An angel is nothing more than a messenger of God and this calling is filled by mankind in their various states of existence.