Q: ls the present Satan the very first original Satan or he has progeny and descendents? If he has, why God created other satans from the one which was already condemned?
A: Yes, Satan is the same original Satan who is named Iblis and who is to survive till Judgment Day.
قَالَ فَإِنَّكَ مِنَ الْمُنْظَرِينَ
إِلَىٰ يَوْمِ الْوَقْتِ الْمَعْلُومِ
“ He said: So surely you are of the respited ones. Till the period of the time made known.”
(Al Hijr, 15:37-38)
Also he has very many children and progeny as mentioned in the Holy Quran:
أَفَتَتَّخِذُونَهُ وَذُرِّيَّتَهُ أَوْلِيَاءَ
"...would you then take him and his offspring for friends ...” (Al Kahf, 1 8:49)
And He also says:
إِنَّهُ يَرَاكُمْ هُوَ وَقَبِيلُهُ مِنْ حَيْثُ لَا تَرَوْنَهُمْ ۗ
"...he surely sees you, he as well as his host from whence you cannot see them ...”
(Al- A’raaf 7:27)
As for the reason of creation of satans and infidels, it is the goodness of creation and imminent invention. On the contrary to refrain from it is stopping of grace and hence undesirable in every condition. What is ready and worthy of coming into existence, Allah would bring it into existence. But the wicked aspects, which arise from some creations like satans and infidels is due to their wrongful choice and, therefore, the condemnation is related to them and not to their Creator.
In other words He created satans and infidels and gave them freedom of choice and also made them responsible, informing them of the things, which would benefit them, but they disobeyed Him and made themselves deprived of good and became sources of mischieves. Thus, whatever is from Allah is all good and nice and whatever is condemnable is from the creatures themselves.
If it is said: What is the wisdom of accepting this origin and what is the benefit in creation of satans? We may reply: One of the wisdoms behind it, is the coming out of some righteous and faithful persons from their progeny like Haam bin Heern. It is obvious that even if only one true believer is born, it is enough to achieve the aim of creation.
It is mentioned in Al-Kafi that if not more than one single believer person is there on the earth, it is sufficient. One of the wisdoms behind the creation of satans is the huge benefit which the believers get by not paying attention to deceptions and doubts raised by them. First ly: satans are means, through which you can differentiate between a righteous and a corrupt character. It is said:
وَمَا كَانَ لَهُ عَلَيْهِمْ مِنْ سُلْطَانٍ إِلَّا لِنَعْلَمَ مَنْ يُؤْمِنُ بِالْآخِرَةِ مِمَّنْ هُوَ مِنْهَا فِي شَكٍّ
"And he has no authority over them, but that We may distinguish him who. believes in the hereafter from him who is in doubt concerning it..." (As-Saba, 34:21)
Secondly, deceptions of satans cause the believer to earn divine grace and salvation if he opposes them. On the contrary, such a person attains a rank higher than that of angels.
Sayyid Abdul Husayn Dastghaib