God appointed us as His vicegerents on earth.

وَإِذْ قَالَ رَبُّكَ لِلْمَلاَئِكَةِ إِنِّي جَاعِلٌ فِي الأَرْضِ خَلِيفَةً

(2:30) And recall the time when your Lord said to the angels, "I am going to appoint a vicegerent on the Earth." ...

'Khalifah' or vicegerent is one who exercises the authority delegated to him by his principal, and does so in the capacity of his deputy and agent. Hence, whatever authority he possesses is not inherently his own, but is derived from, and circumscribed by, the limits set by his principal. A vicegerent is not entitled to do what he pleases, but is obliged to carry out the will of his master. If the vicegerent were either to begin thinking himself the real owner and to use the authority delegated to him in whatever manner he pleased, or if he were to acknowledge someone other than the real owner as his lord and master and to follow his directions, these would be deemed acts of infidelity and rebellion.

We are to serve and obey God on the grounds that God is his Creator and Sustainer, that in His grasp lies man's life and death, that He alone is the Lord Who rules over the entire universe in which he lives. In view of this, the only attitude which can be deemed appropriate for man is one of service and subjection to God.