Kingship Ruling authority of world for Muslims but....

In answer to the question:  

Why Muslims are not granted rule and authority?????'

Hazrat Maulana Ilyas Rahimullah said:

"When you are not applying Allah's commands on your
self and are not stopping your self from doing what Allah has
forbidden, and are not fulfilling those commands of Allah
which are for subjects, (that is, the things whose doing is not
difficult), then, on what ground the administration of the world
be given to you?

The divine intention. behind giving the
believers government on earth, is only that they should run the
system of Allah's commands and wishes in the world.1

When you are not doing this today even in your personal and subject life, how it can be expected for tomorrow from you, giving you the rule?"

1. Reference to a Qur'in  verse: 
"Those who, [even] if We firmly establish them on earth, remain constant ill prayer, and give in charity; and enjoin the doing of what is right and forbid the doing of what is wrong... " [Q. 22:41] 

 'When we are unable to apply Islam on our 6-feet body, how can we apply Islam on others?' says Maulana Muhammad Ahmad Ansari sahib.

The Holy Qur'an says: ' ... Verily, Allah does not change men's condition unless they change their inner selves;.. .' [Quran :13:11]

In its wider sense, this is an illustration of the divine law of cause and effect (sunnat-Allah) which dominates the lives of both individuals and communities, and makes the rise
and fall. of civilisations dependent on people" moral qualities and the changes in 'their inner selves', This reference of 'Allah's way' (sunnatAllah) is twofold: on the one hand, ' are bound to rise high if you are [truly] believers.' [Q. 3:139]

(Taken with thanks from word reflection and footnotes taken from the translator Janab Hafiz Safwan Muhammad page no 36 )