If you are having these dreams and nightmares concerning the Illuminati, satan and his demons then you may possibly be a great threat to them either now or in the future.
When you were an atheist, satan had possession of your soul. Now that you have given your life to Jesus Christ, he's angry and won't stop tempting, attacking and annoying you in some form or another until he can win your soul again, which hopefully he won't. Satan wants all the souls he can get.
You need to learn about spiritual warfare and know that Jesus has given all of His followers dominion and authority over all evil. You must try your best to live a good and clean Christian life in order for it to work though because satan works on legal grounds and open doorways.