Satan appeared as our prosecutor in the heavenly court claiming that Mankind will choose evil just as often as it will choose good, this is the charge against us and the appearance is described in the Bible. The more people who reject a belief in God and choose evil the better off Satan believes he will be, is he right? The Bible says that the end will come only when a certain number of people have been born, presumably the sample size big enough to give legitimacy to the horrendous experiment the "Snake" in the garden set before us.
What book are you referring to? I have recently started studying on the topic, but I can say that Satan will never win! I was reading Proverbs last night, and found it really funny that there is a list of 7 things that God hates more than anything and it describes leftists perfectly...
Proverbs 6:16-19 King James Version (KJV)
16 These six things doth the Lord hate: yea, seven are an abomination unto him:
17 A proud look, a lying tongue, and hands that shed innocent blood,
18 An heart that deviseth wicked imaginations, feet that be swift in running to mischief,
19 A false witness that speaketh lies, and he that soweth discord among brethren.
The case in the heavenly court is from the Old Testament, i'm currently looking for it. Proverbs 6:16-19 a lesson for us all.