(27:66) Nay, but they have lost their knowledge of the Hereafter. They are steeped in doubt and uncertainty about it: rather they are blind to it. After warning the people about their basic errors with regard to Divinity, it is being said that the reason why these people are involved in these errors is not that they have reached this conclusion after serious thought and deliberation that there also exist other beings who are Allah's associates in His Divinity, but the actual reason is that they have never considered this matter seriously. As they are unaware of the Hereafter, or are in doubt about it, or are blind to it, their heedlessness of the Hereafter has developed in them an utterly irresponsible attitude. They are not at all serious about the universe and the real problems of their own lives. They do not bother to know what reality is and whether their philosophy of life accords with that reality or not. For, according to them, in the end the polytheist and the atheist, the monotheist and the agnostic, all will become one with the dust after death, and nothing will bear any fruit.
The theme of the Hereafter is contained in this sentence of the preceding verse: "They do not know when they will be raised back to life." In that sentence it was said that those who are made deities, the angels, jinns, prophets, saints, etc., do not themselves know when will be the Resurrection. Here three things have been said about the common polytheists and the atheists: (1) They do not at all know whether there will be any Hereafter or not; (2) this lack of information on their part is not due to the reason that they were never informed of this, but because they did not believe in the information given to them and doubted its authenticity; and (3) they never bothered to consider with due thought and seriousness the arguments that were advanced about the coming of the Hereafter, but they preferred to remain blind to it.