The Apostle Paul mentions three different callings to illustrate faithfulness -- a soldier, an athlete and a farmer (2 Tim.2:3-6).
Interestingly, each of these requires discipline.
A LOT of discipline.
Now you may not be a soldier, athlete or farmer, but whatever God has given you to do calls for discipline too.
Managing yourself well plays a big part in fulfilling the role God has for you.
Put another way...
It starts with you.
Ruling and cultivating your domain involves getting dominion over yourself first.
And if you struggle with that, remember...
God has given you a spirit of self-control (2 Tim.1:7).
And with His help you can put off the old and put on the new (Eph.4:22-24).