This question has often perplexed many both believer and unbeliever alike. It is deceptively simple yet the answer to the question, if there be an adequate answer causes one to reflect upon both God’s revealed will and His secret council. Hence, as I have reflected upon this question I understand the answer to be found both in God’s revealed Word and in an appeal to mystery. First, the appeal to God’s revelation. One can glean an answer to this question not necessarily in the story of Adam and Eve itself, but by peaking at the end of the Bible in the book of Revelation. In Revelation 13:8 we read,
“All the inhabitants of the earth will worship the beast – all whose names have not been written in the Lamb’s book of Life, the Lamb who was slain from before the creation of the world” – Revelation 13:8
How is it that the Lamb who was slain was slain “from before the foundation of the world?” Apparently, before the foundation of the world, God had always purposed to create man, allow him to fall, and redeem him in the fashion that He has chosen; namely, through the Incarnation of the Second Person of the trinity and giving him as a sacrifice for sin. The answer to our question at hand is wrapped up in God’s eternal purposes. We see the execution of this purpose in the historical redemption of the people that God has chosen to set apart and purchase with the blood of His Son. This biblical truth is grounded in what is called the “eternal covenant”. This covenant was made between the members of the trinity and include the Father promising to give a people to the Son (John 6:39, 17:2, 9, 24). The Son purchases this people with his blood and they are sealed and indwelled by the Holy Spirit. God saw fit that this should be and the outworking of this covenant, God has seen fit to decree so as to take the form and shape that it has in history.
Now an appeal to mystery. Why did God have to actualize a world in which He had to redeem man in the way that he did (i.e., allowing man to fall into sin, thus causing much pain and suffering as a result). The answer to this question is really wrapped up in the simple answer that God had saw fit, in accordance with His own sovereignty, righteousness , and good pleasure, that actualizing such a world adequately and appropriately accomplished His own eternal and righteous purposes; some of which are revealed to us in scripture, and some of which, God has not chosen to reveal to us. I appeal to mystery because I am not aware of all the factors that went into God’s choice to actualize the world that he did. God was free to decree what He has in fact decreed and as a morally pure and perfect being, He must have morally sufficient reasons for setting up the world that He has in the way that he has which takes into account all events that occur in time, both the good and the evil. All things move towards the fulfillment of His purposes. If God had determined to glorify His name and demonstrate both His mercy and wrath by creating a world in which sin would come into existence, He is free to do so. Many may feel uncomfortable with this response, but then again, there is a God, and we are not Him.