Were they? Even before God created the angels, he knew that the one you call Lucifer, would disobey him. It therefore stands to reason, that God created him for that purpose.
No, it doesn't stand to reason. Your thinking here confuses certainty with necessity. It extends the fact that God in His omniscience is certain about what Satan will do into the realm of necessity: If God foreknows what will happen, if He is certain in this knowledge, then it must
necessarily happen. Folks take this to mean that God's certainty about future events
establishes the necessity of those events; His certainty makes it so that the event He foreknows
must happen.
But though God is certain in His knowledge of future events, His certainty is not the
cause of those events. The "certainty" of God only describes
His condition; it doesn't describe
the nature of the event He foreknows. His certainty is a "property" of persons, of conscious, self-aware beings. No stone, or broom handle, or rubber ball can be certain; they don't possess the properties of personhood that are required in order to have certainty. An event, too, cannot be certain, lacking as it does the required aspects of consciousness, self-awareness, etc. in order to be certain. It's not correct, then, to say "Because God foreknew what Satan would do it was
certain that Satan would do it." This is ascribing to an event (what Satan would do) a property only possessed by persons.
Why is this a problem? Well, imagine an expectant mother who says, "My unborn baby will soil its diaper." Knowing as she does the nature of all healthy, newborn babies, that they have no control over their bowel movements, she knows her own baby (if it is healthy and normal), will inevitably, necessarily do the same. Does the mother's certainty about this diaper-filling event make the event
necessary? Does the strength of her conviction that her baby will foul it's diaper make it so that the event
must happen ? No, of course not.
Her certainty doesn't make
the event certain.
In the same way, God's certainty about future events, even though it is far greater than the expectant mother's certainty about her baby's diapers, does not
make the events happen. God is certain in His knowledge of all that Satan will do but it is what
Satan will do, what
Satan's choices will be, about which God is certain. It isn't that God has
determined what Satan will do, thus making his deeds necessary, but only that whatever Satan will, would, or could freely choose to do God knows (and has always known). So, the devil sets his own course and God just knows what it is. If there were some other course that Satan had followed to this present moment, God would have known that course. In either case, though, God's omniscience isn't a constantly, meticulously-determining,
causal factor in Satan's choices; it is only
knowledge - absolutely certain though it is - of what
the devil will, would and could do.
In His omniscience, then, God has always known all that Satan will, would, or could freely do and He uses this knowledge to achieve His will in the midst of Satan's free choices (and the free choices of us all). God is not so small and weak that He must meticulously order everything so that He can "win" in the end. We wouldn't think much of a chess player who could only win under such a circumstance, right? No, God is so amazing, so incredible, so beyond us, that even when we are all of us freely making our own choices about a myriad of things all the time, God, in His omniscience, and omnipotence, and wisdom still achieves His will just as He wishes. Whatever "moves" we make on the "chess board" of our lives, God still "wins" - and handily.
