Is circumcision necessary for Non Muslim; if he want to accept Islam but uncomfortable with circumcision?
Circumcision: is at least a sunna. This means it is permissible and recommended-
According to the Hadith (To find in the Sahih books of al-Bukhari and Muslim, Sunan An-Nasa'i ...)
Abu Huraira reported:
Five are the acts of fitra: circumcision, removing the pubes, clipping the moustache, cutting the nails, plucking the hair under the armpits.
عَنْ أَبِي هُرَيْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم أَنَّهُ قَالَ
الْفِطْرَةُ خَمْسٌ الاِخْتِتَانُ وَالاِسْتِحْدَادُ وَقَصُّ الشَّارِبِ وَتَقْلِيمُ الأَظْفَارِ وَنَتْفُ الإِبْطِ
And also in Sahih Muslim
Abu Huraira reported Allah's Messenger (ﷺ) as having said
that Ibrahim (as) circumcised himself with the help of an adze when he was eighty years old.
عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم
" اخْتَتَنَ إِبْرَاهِيمُ النَّبِيُّ عَلَيْهِ السَّلاَمُ وَهُوَ ابْنُ ثَمَانِينَ سَنَةً بِالْقَدُومِ " .
As Qadi I'yad said: it's sunna with consensus of all the scholares (sunni)...
But this needs a bit analysis as there is no consensus about the ruling, whether it is mandatory and thus a man bears a sin for leaving it, or it is recommended and thus a man gets rewarded and saved from punishment when he does it.
Imam Malik for example: Said it is sunna but considered it more like a fard (farz) this means it's a sin if you leave it! For example Imam Malik didn't accept to do prayer behind an Imam who hasn't been circumcised!
Imam Ahmad and Imam Shafi'i: Also considred it as a wajib/fard (farz)
Imam Abu Hanifa and his Student Mohammed ibn al-Hassan said it's a sunna and not a fard.
Those who said it's more likely to be a fard may have argued using the Verse:
Then We revealed to you, [O Muhammad], to follow the religion of Abraham, inclining toward truth; and he was not of those who associate with Allah .
[Surat an-Nahl (16:123)]
ثم أوحينا إليك أن اتبع ملة إبراهيم حنيفاً وما كان من المشركين
or in an other translation from Sayyid abul a'la Maududi:
Then We sent down this Revelation to you: "Follow the way of Abraham exclusively" and he was not one of the mushriks..."
Abul Ala Maudidi added: Prophet Muhammad (Allah's peace be upon him) was commanded to follow the way of Abraham and not the way of the Jews, and they themselves knew than these things were not unlawful in the law of Abraham. For instance, the Jews did not eat the flesh of camel but this was lawful according to Abraham. Likewise, ostrich, hare, duck, etc., were unlawful in the Jewish law, but they were lawful according to Abraham. Incidentally the disbelievers of Makkah have been warned that neither they nor the Jews had any relationship with Prophet Abraham for he was not a mushrik while both of them were practicing shirk. Prophet Muhammad and his followers were the only true followers of Prophet Abraham (Allah's peace be upon them) for there was no tinge of shirk in their creed or in their practice.
A Fatwa in Arabic.
Circumcision is not a condition to become Muslim!
After all it seems to be the best for him to do circumcision, but one should also take into account the age etc. so maybe under some conditions one should think twice about doing it or not, after all it's more a sunna as Qadi 'Iyad stated!
Note that according to this Fatwa it's not mandatory for a convert and shouldn't be a (major) condition for conversion: This means if the convert fears for himself because of the circumcision he doesn't have to do it.
And Allah knows best