In summarization, Islamic Monotheism is based upon two great pillars and cannot be established except by way of them. They are negation and affirmation. A general all- encompassing negation, negating the right to be worshipped from everything besides Allah, and affirming the right to be worshipped for Allah alone with no partners.
This is because He alone created the heavens and the earth and all therein. He alone provides for and sustains His creation with innumerable blessings and wholesome beneficial provision. He alone is alive eternally and never dies; therefore He alone is worthy of worship.