LDS believe that men will be punished for their own sins, and not for Adam’s transgression.  Thus, there is not a belief in original sin.  The basis of this argument is that the spirit of man was created prior to the fall and is good.

Pre-existence

LDS doctrine teaches that God created man as spirits before the sixth day of creation.  The life you lived as a spirit determines the life you will have on earth with a body.  However, no one has any knowledge of his or her life before birth.  LDS believe that you did not suddenly spring into existence the moment you were born.

Man was also in the beginning with God. Intelligence, or the light of truth, was not created or made, neither indeed can be. (D&C 93:29)

Note:

LDS teach that you were happy in God’s presence, but He knew that you needed more in order to progress. You did not have a physical body like you do now, and you needed a chance to gain experience on your own—away from God’s presence, but with the ability to communicate with Him and receive help. So He sent you to Earth, hoping that you would return to Him and receive everything He has to offer you.

Freewill

LDS believe that one of the most precious gifts God has given people is the ability and power to make choices.  God respects a person’s freedom to choose. He will never force anyone to choose good, nor will He stop anyone from making wrong choices. He knows that by making choices and experiencing their consequences, you learn the difference between good and evil. As you learn to choose good, you find greater happiness.

Children of God

Man is the literal, physical offspring of God (Acts 17:28-29).  LDS believe that everyone is a child of God with a divine nature and a divine destiny. You lived with Him as a spirit before you were born. God sent you to Earth to receive a body and gain the experiences you need to return to Him.

And now, because of the covenant which ye have made ye shall be called the children of Christ, his sons, and his daughters; for behold, this day he hath spiritually begotten you; for ye say that your hearts are changed through faith on his name; therefore, ye are born of him and have become his sons and his daughters. (Mosiah 5:7)