When it considers our first parents and their original sin, the Catechism of the Catholic Church observes: “A spiritual creature, man can live this friendship [with God] only in free submission to God. The prohibition against eating ‘of the tree of the knowledge of good and evil’ spells this out: ‘for in the day that you eat of it, you shall die’” (No. 396). The tree, the Catechism teaches, represents the limits human creatures must be prepared to embrace. We depend upon God; our freedom is subject to God’s law.
God’s command not to eat from that tree in the Garden could not have been clearer; nor could the threatened consequences. That much, at least, Adam and Eve must have known. Likewise, they must have understood they were risking God’s friendship by their disobedience. However, we may assume they were unaware of the consequences for future generations and the results that have been fully explained only by later theologians.