God's creation of beings with free will, including angels and humans, is rooted in His desire for love and genuine relationship. Love and obedience without choice wouldn't be true love. Lucifer, who became the devil, was initially created good, as were all things. However, he chose to rebel against God. The existence of the devil is not a mistake on God's part, but a consequence of the gift of free will.
This brings us to the idea that God's plan includes allowing for the possibility of rebellion, knowing that it would ultimately lead to a greater good and the fulfillment of His divine plan. The presence of evil and the devil in the world provide a backdrop against which God's love, justice, and mercy are demonstrated and realized. Through Christ's victory over sin and death, the ultimate plan of God to redeem and restore creation is brought to fruition.
