No, they have no knowledge of the Hereafter. No, they are in doubt regarding it. No, they are blind to it.
Translation endnotes
[27:66] Having doubts about the hereafter is considered to be similar to not accepting it. The Quran does not accept "faith" as is understood by English speaking people; the Quran expects us to acknowledge the hereafter as a fact, by reflecting on circumstantial evidence abundant around us and within us. According to the Quran, those who do not find the Quran sufficient for guidance, those who do not enjoy mentioning God's name alone, and those who expect the intercession of a savior, do not really acknowledge the hereafter. See 6:113,150; 27:66; 34:21; 39:45; 74:46-48.