Sentence:  This quiet remark serves to remind one, among other things that, Dickens was not without his reasons for a spirit of distrust towards religion by law established, as well as towards sundry other forms of religion--the spirit which, especially in his early career, was often misunderstood as hostility to religion in itself, a <WSD>wanton</WSD> mocking at sacred things. 
Meaning of the word marked with <WSD> tags:  An overly playful person; a trifler.