The Quran

إِنَّ الَّذينَ يُجادِلونَ في آياتِ اللَّهِ بِغَيرِ سُلطانٍ أَتاهُم ۙ إِن في صُدورِهِم إِلّا كِبرٌ ما هُم بِبالِغيهِ ۚ فَاستَعِذ بِاللَّهِ ۖ إِنَّهُ هُوَ السَّميعُ البَصيرُ

Muhammad Asad

Behold, as for those who call God's messages in question without having any evidence therefor¹ - in their hearts is nothing but overweening self-conceit, which they will never be able to satisfy:² seek thou, then, refuge with God - for, verily, He alone is all-hearing, all-seeing!

See note 25 above.
Lit., "which they will never [be able to] reach" or "fulfil". This is a reference to the conceit which makes many agnostics think that man is "self-sufficient" and that, therefore, there are no limits to what he may yet achieve, and no need to assume that he is responsible to a higher Power. Cf. in this connection 96:6-7, which is one of the earliest Qur'anic revelations: "Nay, verily, man becomes grossly overweening whenever he believes himself to be self-sufficient." And since this "self-sufficiency" is entirely illusory, those who build their world-view on it "will never be able to satisfy their overweening conceit". (Cf. also the reference to "arrogant, self-exalting hearts" in verse 35 above.)