God created lucifer. For as long as Lucifer existed, he was disobeying god.
Where do you get this idea that for Lucifer's entire existence he disobeyed God? This isn't what the Bible says.
That means when god was creating Lucifer, he was creating someone who couldn't figure out how to stop disobeying god.
But you haven't shown from any objective, authoritative source that your first premise about Lucifer
always disobeying God is true. So, then, you can't get to this second premise from your first one.
God knew he was doing that. How is that fair to Lucifer?
Well, since your first and second premises that bring you to this question have no basis in objective fact, what point is there in trying to offer an answer? Your question, built upon errors, is illegitimate.
If I were designing/creating something, I wouldn't want to design it with a flaw so fatal that it can't ever be compatible to work well with other people & things, as that would be setting it up for doom.
God made Lucifer with the capacity to choose to serve God or not. In what direction Lucifer exercised this capacity is entirely Lucifer's choice - and responsibility.
Was God unfair to make Lucifer capable of such decision-making? This depends upon what God wanted regarding Lucifer. If God had wanted a robot, a puppet, He'd have made Lucifer incapable of choosing to serve. This was not what God wanted, as we can see from Lucifer's choice to serve himself rather than his Maker.
If a wood carver made a knife of capable of carving wood, in doing so he'd also unavoidably make a knife capable of cutting and stabbing human flesh. Any knife that could carve wood, could carve human tissue. If a thief stole the wood carver's knife and used it to murder someone, would the wood carver be responsible for such an evil use of his knife? He could not have made a knife that could carve wood that couldn't also wound or kill a human being. And he never intended the knife should be used to harm another person. It's purpose was to create things of beauty from wood. So, then, how is the wood carver responsible for the wretched use of his knife? Well, he's not. The
thief is solely responsible for how he used the wood carver's knife.
In the same way, Lucifer used the "carving knife" of his free agency, of his capacity to choose to serve God or himself, to do evil. God intended Lucifer's free agency to produce a good end, but giving such agency to Lucifer unavoidably meant giving him the ability to choose an evil end. Like the thief, Lucifer used the "carving knife" of free agency to do wrong, against its intended purpose. Such use is, then, on Lucifer, not God; Lucifer, like the murdering thief, bears full responsibility for how he uses the "carving knife" of his free agency.
God, then, has never been unfair to Lucifer. Far from it.
