You can be an atheist and still follow the ten commandments as guidelines

[Astreja]

Okay, I've done a little bit of research on the brain's processing of positives versus negatives, and have this to report: 

1. First of all, it's not as simple as it appears.  Most instances I found of the "brain cannot process negatives" trope were on sites devoted to pop psychology rather than peer-reviewed journals.
   
2. Secondly, the actual structure of the statement determines how the brain processes it.  Link:  True or False?  How Our Brain Processes Negative Statements (Association for Psychological Science).  The presence of a negative word does not automatically cause the brain to struggle with it, but the more syntactically complex a sentence is, the longer the reaction time.
   
3. What I found particularly interesting is that the brain processes affirmative and negative statements in different regions.  Link:  Negative and affirmative sentences increase activation in different areas in the brain (Journal of Neurolinguistics - abstract only)
   

It's also noteworthy that emotional content determines how we process and remember things.  Probably for survival reasons, we react more quickly to negative stimuli (not to be confused with negative statements, although it's possible for specific words and ideas to act as triggers).