I find this teaching rather strange - a religion that claims superiority over others because its believers do good deeds out of a self-serving desire to be rewarded by God, in constrast to non-believers who do good out of "politeness or good manners" !  I would have thought that the more noble person is the one who is motivated to do good for no better reason than his love for others or his altruistic spirit !

"… some non-[believers] may do these things out of politeness or good manners, but they are not seeking reward from [god] or salvation of (sic) the Day of Judgement [and they are therefore, by implication, bad]." 

(Some parts of the original text have been paraphrased.  Read the original text here.)