In my own experience, it is the lower self reacting to the changes that the Higher Self facilitates. If you have a Christian/Islamic background (even subconsciously, as is the case for many people who think that they are free from Abrahamic influence), the “defense mechanisms” that those programs implanted in your mentality revolt. Although, this can occur regardless, because nature at this level of consciousness seeks to keep you the same, so if you want love, it tells you that you don’t deserve it; if you want to learn, it says you're too stupid; if you want faith, it tells you that the Gods don’t exist.
Ignore all negativity that unconsciously presents itself, for it is not your Will and that of the Gods. Zevism restores the mind, body, and soul. With consistent practice and study, mental clarity is yours. Good Luck!