﴿ وَلَا يَزَالُ ٱلَّذِينَ كَفَرُوا۟ فِى مِرْيَةٍۢ مِّنْهُ حَتَّىٰ تَأْتِيَهُمُ ٱلسَّاعَةُ بَغْتَةً أَوْ يَأْتِيَهُمْ عَذَابُ يَوْمٍ عَقِيمٍ ﴾

“whereas those who are bent on denying the truth will not cease to be in doubt about Him until the Last Hour comes suddenly upon them and [supreme] suffering befalls them on a Day void of all hope.”

A prophet’s call is marked by the greatness of convincing arguments. But those who are accustomed to seeing only outward greatness, are unable to detect the inner greatness of the prophet and consequently deny it. Such people are always in doubt because they want to see the Truth in external glory. And it is the way of God that He brings Truth in the abstract to people, so that those who recognise Truth may acknowledge it and attach themselves to it and those who are enamoured of outward show may ignore it and prove themselves finally guilty. Denying the signs means that man ignores the Truth, even when it is supported by sound argument. He is not willing to accept the Truth, even if it is staring him in the face.