ولا يزال الذين كفروا في مرية منه حتى تاتيهم الساعة بغتة او ياتيهم عذاب يوم عقيم

وَلَا يَزَالُ ٱلَّذِينَ كَفَرُوا۟ فِى مِرْيَةٍ مِّنْهُ حَتَّىٰ تَأْتِيَهُمُ ٱلسَّاعَةُ بَغْتَةً أَوْ يَأْتِيَهُمْ عَذَابُ يَوْمٍ عَقِيمٍ

 
We see previous themes from other verses reemerging in these verses (and ones following).  

Allah is mentioning the risk of shaitan's influence, and earlier in the surat, we see examples of this risk: those who 'turn their necks in arrogance' and those who 'worship Allah on an edge.' It also reminds us of the people of faith that misconstrued the words of their prophets (pbut), such as those entioned in verse 17. The same description of Shaitan's influence being a trial to further punishment for disbelievers because of the extent of what they've allowed their hearts to become in ayat 53 is referenced in ayat 44. The mention of diseased hearts isn't only in verse 53, but also described further in verse 46, where hearts are described as 'blind.'

Allah brings up knowledge regarding revelation in these verses. Earlier in the surat, Allah describes the opposite scenario: what happens to those who do not embrace the gift of knowledge of revelation. The surat is coming full circle.

The main purpose of Hajj is to ‘remember Allah’

-10 days of dul-Hijjah, Allah says: 

   'That they may witness benefits for themselves and mention the name of Allah on known days…..'[hajj:28]

-in Muzdalifa, Allah says:

 'But when you depart from 'Arafat, remember Allah at al- Mash'ar al-Haram. And remember Him, as He has guided you, for indeed, you were before that among those astray.[Al-Baqara:198]

-days of Tashreeq , Allah says : 

'And remember Allah during [specific] numbered days. …[Al-Baqara:203]

-when slaughtering Qurbani

' And for all religion We have appointed a rite [of sacrifice] that they may 'mention the name of Allah ''over what He has provided for them of [sacrificial] animals. '[Al-Hajj:34]

'  Their meat will not reach Allah, nor will their blood, but what reaches Him is piety from you. Thus have We subjected them to you that you may glorify Allah for that [to] which He has guided you; and give good tidings to the doers of good.'[Al-Hajj:37]

- End of Hajj, Allah says:

' So when you have accomplished your Manasik [(i.e. Ihram, Tawaf of the Ka'bah and As-Safa and Al-Marwah), stay at 'Arafat, Muzdalifah and Mina, Ramy of Jamarat, (stoning of the specified pillars in Mina) slaughtering of Hady (animal, etc.)]. ''Remember Allah as you remember your forefathers or with a far more remembrance.' '[Al-Baqara:200]

In verse 1, put simply, God did not come to play. Allah sets the scene for very serious warnings. Allah uses the world 'zalzalat' in reference to the Day of Judgement, and while it refers to the physical quaking/shaking of the Earth, we can understand it as so awe-strikingly terrifying that it 'shakes' each creation of Allah; human, jinn, animals, and even mountains.
In the second verse, Allah describes events we find incredibly off-putting in the dunya. We frown upon the drunkard in the street and we could not even imagine our disgust at the mother who leaves her child in harm's way willingly and we are grief-stricken by the thought of a woman miscarrying. The severity of these events, again reflect the severity of the events of the Day of Judgement. I often find myself saying that the best time to understand the true nature of someone is in the extreme circumstances (usually stress). That's when the nature of the heart shows (is the person truly patient? Merciful? Steadfast? etc). In the extreme stress of that Day, the true nature of mankind will show. That true nature is one of khashya (awe-inspiring fear) of Allah, one of undenounced belief in the One Lord and in His qualities that are neither restricted or bound by any physical law. 
The miscarriage portion is interesting in that we understand physiologically that extreme emotional stress can result in spontaneous abortion. But interesting to note is that, at that point, there is no more earth for that possible child to dwell in the first place. #DayofJudgement  #SuratAlHaj 

One of the first things we learn about are the stories of Prophets. And one of the first things we forget about as we grow in our knowledge of the complexities of Islam are... the stories of the prophets (may Allah's blessing be on them). It's very interesting because they are a wrought reminder to us of the very patterns of self-destruction that exist today. From heedlessness to arrogance to sticking to the status quo because it was 'what our forefathers left us' aka 'all we've ever known.' I'm reminded of the understanding that Allah does not destroy a nation unless it is unjust/oppressive, whether a Muslim nation or Kaffir nation. #SuratAlHaj