আপনি কি লক্ষ্য করেননি যে, আমি কাফেরদের উপর শয়তানদেরকে ছেড়ে দিয়েছি। তারা তাদেরকে বিশেষভাবে —(মন্দকর্মে) উৎসাহিত করে।

Let’s take a Critical Reasoning (intermediate level) on this Ayah:

Bismillah.
“How come a Most Merciful Creator sends evil unto men?
It doesn’t make sense!”
Is this question resonate to you?

First of all, I am not giving an apologetic clarification to the kuffar.
I don’t bother at all how would they take it or how further away this Ayah might take them from Islam.
The guidance is up to Allah, Al-Hadee.
He guides whoever He wills.
Even He guided the most wretched, He, the Most Merciful even sent a messenger to the most wretched one (Firaun, The Farao, Al Quranul Kareem 79:17).
He guided the one who was the most staunch enemy of Islam.
He guided the killers of the Muslims.

Apparently, this Ayah might be another reference to the enemies of Islam to use their false propaganda against Islam. Let them be. They make plans and Allah Subhanahu makes a plan and Allah is the best planner.

Therefore, I will direct my reasoning to the Muslims in Kuffar’s Mindset ONLY.

Know Your Status:

If you think you are a Muslim and yet this Ayah make you little uncomfortable, know that it is because you have a status and that status is that you have a Kuffar’s mindset though you think you’re a Muslim because you do some rituals of Islam but in reality, Kuffar has shaped your mind long back.

And actually, it’s not only you.
Your fathers, few generations back have been in the Kuffar’s Mindset (whoever applicable).
Kuffar had a plan to take your father’s out of Islam 200 years back.

Therefore, you have to understand this, your status or otherwise, nothing I say will make sense to you.
You will be dipped into more confusion.
I ask Allah, Al-Fattah to open your heart.

A Simple Math:

Did He, Subhanahu wa Ta’la inform you that He created Jahannam, Hell? (Sunan Nasai 1947)
Did He inform you that He created Men for Fire? (Al-Quranul Majeed 32:13, Abu Dawud 4713).
Did He inform you that He did not create men playfully? (Al-Quranul Majeed 23:115).
Did He tell you that had this Quran been sent on a mountain it would have exploded out of fear of Allah? (Al-Quran 59:21)

Tell me, Were these Ayat had any impact on you?
If this Ayah (sending shaitan) makes you uncomfortable then creating of Jahannam should make you million times more uncomfortable!
But how easily you took that and had no fear about it.

Tell me, do you really believe that Jahannam is true?
If you do, then know that Jahannam has many levels too (Al-Quran 4:145 and Saheeh Bukhari 6562, Saheeh Muslim 213).
And therefore, ask yourself again, why Jahannam has also many levels? Because all Kuffar are not of the same level.
He, Al-Azeez, wanted some Kuffar to be the most wretched so that He can put them to the lowest level of Jahannam and how can He make them be such wretched expect they be helped by shaitan?
It all goes with the simple math!
If Jahannam is true then sending a shaitan to fill that Jahannam should not get you in surprise.
It’s a SImple Math!

And for the Kuffar, the easy solution is Just to
(1) believe in Allah,
(2) believe in the Quran and
(3) believe in the messenger Muhammad salla Allahu alaihi wa sallam. That’s the minimum things He, the Most Merciful asked for.
If you don’t have that belief then why the Kuffar should even bother what the Quran says!

A Mercy from the Most Merciful:

Do you understand the cost of your breath?
Do you really understand the worth of your one organ?

Tell me if you, by a chance, loss an organ (May Allah protect you) and you find a person who gives you that organ, how grateful you would be to such a benevolent person for your entire life?
Then what do you think about your RABB, who gave you all these organs? How benevolent he has been to you?
Then what gratefulness you showed to your creator in your entire life? Think about it!

And then tell me, if a most wretched person threatens you, who can do to you whatever he likes and against whom you have no power, how would you fear him, how would that terrify you?

Then what about the Most Powerful, the creator of the Sun?
Don’t you look at the Sun, how powerful it is?
Doesn’t it make you humble to fear its creator?

Point is, since those Ayat do not have any impact on you, then why is this Ayah bothering you anyway?

But For Allah, Subhanahu wa Ta’ala to threaten by Jahannam and sending saitan doesn’t make Him wretched (Aujubillah), rather it is His mercy that if the threat of fire should make you fear Him now and make you submit to Him now.
And if you do, then you will obey His command and stay away from what is forbidden for you thus He can admit you in paradise!
That’s His mercy to you.

And Allah knows best.
Anything good from this is from Allah only and anything bad is from my own nafs.
May Allah forgive me for my shortcomings.
And I ask Allah to guide you and remove confusion and doubt from your heart and make you submissive to Him.
Ameen.