In the premortal existence, a grand council was held and Heavenly Father presented to us his plan for our salvation. We were so happy that we shouted for joy (see Job 38:7).
Elder L Tom Perry (Oct 2006) said:
What occurred in this first estate is dimly understood, but we do know that we lived there as spirits, children of our Heavenly Father, and we made certain steps of advancement to prepare for the opportunity of housing our eternal spirits in earthly bodies. We also know that our Father held a great council to explain the purpose of earth life. We had the opportunity of accepting or rejecting the plan of salvation. It was not forced upon us. The essence of the plan was that man would have an opportunity of working out his own salvation on earth, with God’s help.
This plan, which was set out before the beginning of time, required that someone must come to earth would atone for the sins of mankind.
Joseph Smith told us that: “At the first organization in heaven we were all present, and saw the Savior chosen and appointed, and the plan of salvation made, and we sanctioned it.” (Teachings of the Prophet Joseph Smith, p. 181.)
Moses, through revelation, gives us some of the details of that grand council “Satan … came before me, saying—Behold, here am I, send me, [and] I will by thy son, and I will redeem all mankind, that one soul shall not be lost, and surely I will do it; wherefore give me thine honor.
Then the Lord continued: “But, behold, my Beloved Son … said unto me—Father, thy will be done, and the glory be thine forever.” (Moses 4:1–2)
Abraham quotes the words of the Lord when he said: “Whom shall I send? And one answered like unto the Son of Man: Here am I, send me. And another answered and said: Here am I, send me. And the Lord said: I will send the first.
“And the second was angry, and kept not his first estate; and, at that day, many followed after him.” (Abr. 3:27–28.)
As part of that plan, Jesus Christ was born onto the earth, the child of a mortal mother and a divine Father, more than 2000 years ago.
While he was on the earth he did many great and wonderful things – he taught the gospel, he healed the sick, he established a church, he bestowed priesthood authority. Important as all of these things were – they were not the reason he came to earth. He came into this mortal existence to carry out the assignment that he had accepted in the pre-mortal existence; to fulfil his foreordained mission to atone for the sins of the world and thus facilitate his Father’s great plan of salvation for His children.