There is a difference between our nature and the habits we develop. The Quran says: "And follow the nature [constitution] as made by God, that nature in which He has created mankind." (30:30) God has created everyone on upright nature. There is no defect in nature. But we do acquire wrong habits. People take things for granted. For example, I am breathing. This is taken for granted.

People think they will forever keep breathing, although if we do not get Oxygen from God we will not be able to breathe. People generally take things for granted. People do not think. God has supplied more than 99% of the things to us. We receive less than 1% by our own thinking. When you go to the market, you think you need a glass and you buy one. 
You thought that you needed to buy a glass. But there are thousands of factors responsible in the making of glass. You did not think of these factors, because you took them for granted. People do not think.

The last part of Surah Al-Imran says that one understands matters by thinking. By thinking, you recognize the Prophet and you discover your limitations.  The problem is that people do not think. They do not engage in reflection and contemplation. Because God is continually providing us with things.
The sun is sending light and heat. The air is supplying Oxygen. There is right amount of gravity in place on earth. Everything in happening on its own. We only think of things which we do. This is a very small fraction of all that is happening. We do not think about things outside of what we do. People need to develop a habit of thinking. The Quran has been revealed so that people ponder over its messages. (38:29) A person can gain everything by thinking. All kinds of spiritual and intellectual development can be had by activating our thinking process.