Why did God harden Pharaoh’s heart?

Why did God harden Pharaoh’s heart? Was it unjust for God to harden the heart of Pharaoh and then punish Egypt for what Pharaoh did as a result of his hardened heart?

Why did God give us free will?

Why did God give us free will? If God knew what the results would be, sin and evil, why did He give humanity a free will?

Why did God give us free will?

Why did God give us free will? If God knew what the results would be, sin and evil, why did He give humanity a free will?