Arrogance and pride (istikbar) as a barrier to faith

إِلَّآ إِبْلِيسَ ٱسْتَكْبَرَ وَكَانَ مِنَ ٱلْكَـٰفِرِينَ

Except Iblees; he was arrogant and became among the disbelievers.