Why should we worship Allah?
It is happened somebody asks: When Allah doesn’t require the worship of anybody, why should we worship Him? He is needless and all are dependent on Him. If Allah needs our worship, then it is not agreeable to His divinity and Godhood.
Answer: Now its answer can be given in two ways: one in brief and the other in detail.
The brief answer is that when the purpose of this worship is to fulfil the needs of Allah and by obeying Him we give some benefit to Him, then the question arises that Allah is unlimited and away from all defects and needs; then what is the need for our worship, but the purpose of worshipping Him would be to elevate ourselves, then the worship would be a means to elevate ourselves and for goodness and it will a favour and guidance from Allah to make us reach perfection through worship.
The detailed answer is as follows: Worship, supplication and whatever deed is performed for pleasing Allah, more or less it has the effect on the person and society also. In fact these are the highest training and ethics in the school of Islam because:
a) The worship of Allah creates a sense of thankfulness, respect and honour. To realize the value of the source from where man gets the valuable divine blessings is a sign that the person was deserving of them.
b) The worship of Allah elevates the soul of man. What else can be more elevating that he gets connected to the total perfection and that is Allah, and for the duties of worship and the affairs of this life we ask help from the unending and unlimited power and acquire that much capability that we can communicate with Him.
Source: al-islam.org
Other links:
Monotheism (Advantage of Discussion about the Outlook on Universe)
Monotheism, the First Principle of Divine Outlook on Universe
Monotheism (What is Natural Disposition?)
Monotheism (Is Obedience a Negation of Man’s Freedom?)
The Shortest Path to God