When God placed Adam and Eve in the Garden of Eden, He gave them two commandments. The first was to “multiply and replenish the earth” (Moses 2:28) and the second was not to partake of the fruit of “the tree of the knowledge of good and evil.” (Moses 3:16-17; Genesis 2:16-17).
Then Satan came and tempted Eve, she partook of the forbidden fruit, and persuaded Adam to do the same. As a consequence of their disobedience, Adam and Eve were cast out of the Garden of Eden, out of our Heavenly presence, which was a spiritual death. Being cast into the world made them mortal and subject to physical death, BUT it also meant they could fulfill the commandment to have children.
If Adam and Eve had stayed in the Garden of Eden, they would’ve remained innocent and the rest of us would still be waiting in the pre-existence. Adam and Eve’s choice to eat the forbidden fruit allowed our Heavenly Father’s plan of happiness to commence, enabling us to come to earth, receive bodies and be tested. Our Heavenly Father then provided a Savior and Redeemer for all of mankind, His only begotten son, Jesus Christ. Only through Jesus Christ are we saved from both spiritual and physical death.
“With prophets ancient and modern, I testify that “all things have been done in the wisdom of him who knoweth all things.” Thus, from the moment those first parents stepped out of the Garden of Eden, the God and Father of us all, anticipating Adam and Eve’s decision, dispatched the very angels of heaven to declare to them—and down through time to us—that this entire sequence was designed for our eternal happiness. It was part of His divine plan, which provided for a Savior, the very Son of God Himself—another “Adam,” the Apostle Paul would call Him5—who would come in the meridian of time to atone for the first Adam’s transgression. That Atonement would achieve complete victory over physical death, unconditionally granting resurrection to every person who has been born or ever will be born into this world.” -Elder Jeffrey R. Holland, of the Quorum of the Twelve Apostles (Where Justice, Love and Mercy Meet).
I am a member of The Church of Jesus Christ of Latter-day Saints. You can learn more about my faith here.