Deadlift said:
God was not very kind in the old testament and Satan was not evil at all.
We have to look deeper to see the truth of this. Having a background in Christian studies (I have a degree in Christian Ministry), this would appear to be true on the outside but upon further look is as far from accurate as can be. It is true that Satan is not a developed character in the Old Testament, but we can see his works.
In the beginnings of the world, God had to be somewhat of a disciplinarian. His goal was to build a nation, a people that could be called His. In order to do this, He had to bring judgment on the world, in particular those who had the bloodline of the Nephalim, the fallen angels, because they were wicked beyond repair. So, He brought a flood and saved Noah, the only pure human.
Eventually the Jews ended up in captivity in Egypt. God had to bring them out to their own land. So, he brought plagues upon Egypt because Pharoah was stubborn and hardened beyond repair.
When the Jews did get their own land, they seldom followed God. Nearly every chapter in Kings and Chronicles shows Israel in some sort of idolatry, whether to Baal or Molech or another foreign idol. So after sending prophet after prophet whom the Jews would not heed, he let them be conquered by Persia.
All of this was done in an attempt to bring people back to Him, to make a people who would be His light in the world. None of it was vindictive or unkind.
But who was behind the Nephalim? Lucifer.
Who was behind the kingdom of Egypt and its gods? Lucifer.
Who was behind Baal and Molech? Lucifer.
So while we never see Lucifer in his Lair of Evil wringing his hands gleefully (in fact the only time we do see him is in the book of Job, where he is petitioning God to persecute an innocent man), we do see that God continually has to deal with his works.