O mankind! Worship your Lord (Allâh), Who created you and those who were before you so that you may become Al-Muttaqûn (the pious - see V.2:21).

Allah who loves us more than our mother and father, (because he is our creator and provider), is telling us that we should be connected with Allah all the time, and realize his powers and controls upon us.  He is the one who gave us our souls in the mother's womb when we were a fetus. And showed us his examples of those nations of the past, regardless of their status, fame, or wealth.  Allah was also their creator and provider for those who are no longer in this world. But we can see tall buildings, and lots of beautiful architecture from history, but one may ask where are those people today, who made those things with their hard work, and their best thinking. They had the trust of that they will never loose their achievements, when they were completing building their goals.

We can see in major cities today such as New York, Chicago, London, Paris, or the time of the Islamic government that ruled Spain, and many more examples. But all of their efforts are now useless unless someone made something like a mosque (masjid) or a Islamic school.  Only those efforts are being counted for those builders, who wanted to save their hereafter. We can see the examples of the Prophet, and his companions, they never left any buildings, or monuments, the only thing we have  are their actions and good deeds which people will apply until the day of judgment, and it is good deeds which will help them after death.