2 Nephi 2:23-5; “And they would have had no children; wherefore they would have remained in a state of innocence, having no joy, for they knew no misery; doing no good, for they knew no sin. 24 But behold, all things have been done in the wisdom of him who knoweth all things. 25 Adamfell that men might be; and men are, that they might have joy.”
Romans 5:12-14; “Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned: 13 (For until the law sin was in the world: but sin is not imputed when there is no law. 14 Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam’s transgression, who is the figure of him that was to come.”
This is dualism.