this thought has always bothered me too, the angels and Adam and Eve were perfect were they not, with free will, then when they decided to use their choice they became imperfect and so Satan and his cronies were cast out blah blah blah,
so after much time (a few weeks God's time) Jehovah has a few faithful followers and the earth is returned to a paradise and they were made perfect. I'm guessing all these perfect people and the angels still have their free will otherwise what's the point - Jehovah may as well have a load of robots running around (or is that what dubs are?!)
so in this paradise someone decides to do something interesting and sin, and recruit a few followers then next thing you know is a whole new soddom and gomorrah has established it self so Jehovah has to go through the whole process again, poor old Jesus will have come come back and get crucified again . .
Just think, Jehovah is probably experiencing his whole own groundhog day!