Adam and Eve were in a state of innocence when their bodies had been created, and they then put in them and brought to life. This is similar as a child from birth. Innocent, without understanding the difference between right and wrong, because they do not comprehend it in it’s fullness.
It is for this reason that children, until they reach the age of eight years old, when science has determined that a child’s brain and development has reached a certain maturity of state, in which they are fully accountable for the actions they commit, that they are considered by the Lord accountable and ready for baptism.
Jesus Christ, through His atonement, has made provision for children, as also Adam and Eve, when they were not fully accountable, by covering their transgression personally, so that they were okay to move forward.
This is why Adam and Eve’s action against the Father’s commandment is called a transgression, rather than a sin, because they didn’t comprehend the full weight of their disobedience. It wasn’t until Adam and Eve later fully gained the understanding of the knowledge of good and evil, that they needed repentance of sins and baptism.
Some individuals will never need baptism and repentance, because of a handicap or disability, which stays with them until they pass from this life, and that’s also a part of God’s plan for that person.
Even though Adam as Eve’s transgression was fully covered, there are still consequenses, as in Adam and Eve introducing sin and death into the world, through partaking of the forbidden fruit.
Sins do need repentance, and there are also still consequences, even after repentance, such as in the case of a young couple who engage in pre-marital sexual relations, and fully repent, but bring a child of God into the world. Yet God makes all things good, as a child born out of wedlock, bringing great blessing to the world, and those around them.
Had Adam and Eve not partaken of the forbidden fruit, their bodies would not have changed in a way to ever die, nor could they physically have children. It was the fall which changed their bodies, making them able to have children.
Because of Adam and Eve, after death we can now return to God for proper judgement, and then enjoy what ever kingdom of glory we merit through the merits of Christ, as we observed.
The earth life of God’s children is to help us become more like Him, as a child can become like their parents.
The fall was meant to happen, so that God’s great plan of happiness could continue, and children could leave pre-mortal life, come to earth and be tested, learn and grow, and have all the necessary earthly experiences required, to eventually become like Him in the eternities.
The Atonement from Jesus Christ was not brought about to fix an unforseen accident by Adam and Eve, in there being a forbidden tree in garden in the first place, but rather, earth life and the fall and atonement, are the central parts of God’s plan from the beginning.
In this our Savior had prepared for, and accepted His role to come do what only He could do, and help us become clean, new, grow, and perpetually become as He and our Heavenly Father or Mother someday.