Give me pieces of iron – till, when he had leveled up (the gap) between the cliffs, he said: Blow! – Till, when he had made it a fire, he said: Bring me molten copper to pour thereon. (96) And (Gog and Magog) were not able to surmount, nor could they pierce (it). (97) He said: This is a mercy from my Lord; but when the promise of my Lord cometh to pass, He will lay it low, for the promise of my Lord is true. (98)
Zulqarnayn made the iron wall sealed with molten copper. When he was thanked and a reward was offered he said: This is from the mercy of our Lord, and when the time comes (Akhirah) He will undo it and the only thing, which will remain, will be Haq or the truth.
Islam does not stop progress as in using iron and making factories, setting up industry, drilling oil, but at the same time if we make something without an eye on Akhirah and then become arrogant about it and think that this is our own achievement, we become self inflated with our arrogance. Thus instead of being just and kind to other nations (such as Zulqarnayn was) one becomes oppressive in ones arrogance, this is not permitted. Creating pollution, and killing the life in the ocean and air is not permitted, as it is unjust.
Building things in which only a few individuals benefit and the rest (humans, animals and sea life) starve and are exploited this is forbidden.
Nowadays these attractions lead one to join a race to climb the ladder of material success. These attractive goals have been coupled with such hurdles and such carrots being placed in front of men and women that they forget their spirituality, their families and their eye is only on their individual growth and the growth is such that begins and ends in this world with nothing invested for the future (Akhirah).
This vicious circle of a career with no end to work with the sacrifice of the family and society has destroyed people. This is modern day slavery, whereas it is designed in such a manner that people go into it voluntarily.
Surah Noor 24: 39
As for those who disbelieve, their deeds are as a mirage in a desert. The thirsty one supposeth it to be water till he cometh unto it and findeth it naught, and findeth, in the place thereof, Allah Who payeth him his due; and Allah is swift at reckoning. (39)