What is the shudder mentioned in the verse, is it the body trembling out of awe, and does this mean that whoever does not experience this state does not fear Allah?

Allah described His believing servants as those whose skins shiver, whose hearts tremble, and whose eyes weep out of awe when Allah is mentioned and the Quran is recited, as in His Almightyقول: (Allah has sent down the best statement: a Book consistent with itself and oft-repeated. The skins of those who fear their Lord shiver from it; then their skins and their hearts relax at the mention of Allah). The shivering is the bristling and rising of the hair on the skin from fear and dread, accompanied by trembling, awe, tranquility, and reassurance. As for the shouting, screaming, and severe agitation performed by some innovators, it is from the work of Satan. The absence of this shivering does not mean that the reciter or listener is not among those who fear Allah, but it may indicate a deficiency in their state of perfection and awe.