Quran 21:44 – “We gave the good things of this life to these men and their fathers until the period grew long for them; See they not that We gradually reduce the land (in their control) from its outlying borders? Is it then they who will win?”
Sayyid Abul Ala Maududi – Tafhim al-Qur’an – The Meaning of the Qur’an
44 In other words it means: “These people have been deluded by Our favor and Our provisions. They think they are enjoying prosperity and good life as their personal right and there is none to take it away from them. They have forgotten that there is God above them Who is able to make or mar their fortune“.
45 In this connection, see Ar-Ra`d (XIII): 41 and E. N. 60 thereof. Here it bears an additional meaning also: “Do they not see that an All-Powerful Being is showing His Signs every now and then everywhere on the earth in the form of famines, epidemics, floods, earthquakes and other calamities; millions of people are killed, habitations and harvests are destroyed and other damages are caused, which frustrate all human designs?”
46 It means: “When they know that all the resources and provisions of life are in Our hands and that We can increase or decrease them as We will, have they the power and strength to defend themselves against Our punishment? Can they not see from these “Signs” that their power, prosperity and luxury are not everlasting and that there is an All-Powerful Allah to seize and punish them?” 
 Sayyid Abul Ala Maududi – Tafhim al-Qur’an – The Meaning of the Qur’an – http://www.englishtafsir.com/Quran/21/index.html#sdfootnote44sym