Verse 6

As to those who reject faith, it is the same to them whether you warn them or do not warn them; they will not believe (Inna alladhîna kafarû sawâun 'alayhim a' andhartahum am lam tundhirhum lâ yu'minûn)

Its positioning [and relationship with what precedes it]:

Consider this: in the world of His pre-eternal attributes, the Unique Being has two manifestations, those pertaining to His Glory and those pertaining to His Beauty. Through their manifestation in the world of the attributes of actions, they appear as grace and wrath, and goodness and majesty. Then inclining to the world of actions, adornment and embellishment (tahliya, tazyin) arise, and demonstrate that the Creator is exempt from the attributes of creatures (takhlîya, tanzîh). Then, being imprinted on the world of the hereafter, which is one of the worlds of works ('âlam al-âthâr), grace is manifested as Paradise and light, and wrath is manifested as Hell and fire. And being reflected in the world of remembrance, recollection is divided into praise (al-hamd) and glorification (al-tasbîh). And being represented in the world of speech, they diversify into command and prohibition. And being depicted in the world of guidance, they divide into encouragement and restraint, and reassurance and warning. And through their manifestation in the conscience, hope and fear are born. And so on. Moreover, it is the mark of guidance to preserve the balance between hope and fear, in order that hope may induce striving and work, and fear may restrain from transgression, and a person will not despair of divine mercy and opt out in blameworthy fashion, or feel sure he will not be punished so unconcernedly go astray. It is because of this successive wisdom that the Qur'an does not encourage without restraining, nor praise the righteous without censuring sinners.