Allah's guidance, shivering of the skin and then relaxing of skin and hearts on remembrance of Allah

أعوذ بالله من الشيطان الرجيم 

Az-Zumar 39:23

ٱللَّهُ نَزَّلَ أَحْسَنَ ٱلْحَدِيثِ كِتَٰبًا مُّتَشَٰبِهًا مَّثَانِىَ تَقْشَعِرُّ مِنْهُ جُلُودُ ٱلَّذِينَ يَخْشَوْنَ رَبَّهُمْ ثُمَّ تَلِينُ جُلُودُهُمْ وَقُلُوبُهُمْ إِلَىٰ ذِكْرِ ٱللَّهِۚ ذَٰلِكَ هُدَى ٱللَّهِ يَهْدِى بِهِۦ مَن يَشَآءُۚ وَمَن يُضْلِلِ ٱللَّهُ فَمَا لَهُۥ مِنْ هَادٍ 

Allah has sent down the best statement: a consistent Book wherein is reiteration. The skins shiver therefrom of those who fear their Lord; then their skins and their hearts relax at the remembrance of Allah . That is the guidance of Allah by which He guides whom He wills. And one whom Allah leaves astray -  for him there is no guide.