Question:
God certainly knew that Lucifer would fall. So why was Lucifer created? The same question applies to Adam—God knew that Adam would fall as well.
Answer:
These are issues that, upon reflection and study, we can begin to understand. No true character can be formed without a test. Without testing, a being is merely a mechanism without will. However, those characters who are worthy of enduring forever are those who choose to serve God voluntarily, without coercion, simply because they love Him and desire to do His will.
On the other hand, a person who chooses to obey can also choose to disobey. God knew that some would make this choice. Yet, even for these individuals, He does not abandon them in their misery and transgression. Instead, He calls to them and assures them that where sin abounds, grace abounds even more. Thus, even if His creatures fail, He has opened a glorious path for them to return. This principle applies equally to Lucifer and the fallen angels, just as it does for humanity. Unfortunately, they chose not to return; they continued down their own path. Nonetheless, the Lord will use even the rebellion of those who oppose Him to teach a glorious lesson that will echo through eternity, showcasing the wonderful love and justice of God.
We might not comprehend all these matters fully, but God is working them out for His glory and for the highest good of His creatures. As “the father of the faithful” asks, “Shall not the Judge of all the earth do right?” The redeemed, for all eternity, will answer, “Just and true are Thy ways, Thou King of saints.”