When Adam fell, it was as if the human race had fallen into a pit, from which they were powerless, by any act of their own, to emerge; having no means whereby to climb up and out, and not even knowing how to climb [or that they need to climb].
But a Friend, all-wise and all-powerful, comes to the mouth of the pit, Compassionates its wretched inmates, and proposes to rescue them from their unhappy situation. He makes of his own life a ladder lets it down into the pit and says: "Now climb!" They who climb, get out of the pit. They who refuse to climb, remain in the pit—and who is to blame but themselves? (Conference Report, October 1927, 149)
A man walking along the road happens to fall into a pit so deep and dark that he cannot climb to the surface and regain his freedom. How can he save himself from his predicament? Not by any exertions on his part, for there is no means of escape in the pit. He calls for help and some kindly disposed soul, hearing his cries for relief, hastens to his assistance and by lowering a ladder, gives to him the means by which he may climb again to the surface of the earth.
This was precisely the condition that Adam placed himself and his posterity in, when he partook of the forbidden fruit. All being together in the pit, none could gain the surface and relieve the others. The pit was banishment from the presence of the Lord and temporal death, the dissolution of the body. And all being subject to death, none could provide the means of escape.
Therefore, in his infinite mercy, the Father heard the cries of his children and sent his Only Begotten Son, who was not subject to death nor to sin, to provide the means of escape. This he did through his infinite atonement and the everlasting gospel. (Doctrines of Salvation, 1:127)
So the effect of Adam's transgression was to place all of us in the pit with him. Then the Savior comes along, not subject to that pit, and lowers the ladder. He comes down into the pit and makes it possible for us to use the ladder to escape. (Doctrines of Salvation, 1:123)