Throughout the Quran there are numerous verses enjoining the reader to observe and reflect on the universe and the phenomena of nature. A verse in chapter 3 says:

There are signs in the creation of the heavens and the earth, and in the alternation of night and day for people of understanding. (Quran 3:191)

This is because the Quran wants people to discover God through study and contemplation. God should be an intellectual discovery for believers.

God wants that people should stand on self-discovered faith and does not want faith to be imposed upon them. He has given intelligence to human beings so that they can evaluate and make a self-discovery of the truth. The spirit of enquiry is essential for this self-discovery.

Source: The Seeker’s Guide

Everything in the universe sends out the message of God-realisation in natural terms as if the entire universe is an excellent library of God-realisation. When a thinking person reflects, he discovers incredible miracles of creation, from his existence to the rest of the universe. Then, he spontaneously calls out that, without a doubt, there is a Creator of this universe and that he should acknowledge Him and surrender before Him. The library of the universe is an absolute treasure of the realisation of God. Belief in God is another name for this conscious discovery. This belief, or realisation, is an intellectual revolution of nature that transforms man’s entire personality. With this belief, a new spiritual (Rabbani) personality emerges. The realisation is the beginning of faith. It means trying to recognize God through the observation of His creation. By discovering signs in the creation, we can discover God. Another name for this is conscious discovery of one’s Creator.

Source: Discovering God

The physical universe is the subject of scientific study. But what is the physical universe? It is the creation of a Creator. The study of the universe is, in an indirect way, the study of the work of the Creator. In this sense, modern science is modern theology. Evidence of God is spread throughout the expanding universe.

The issue of God is the issue of the Creator of the universe. It is the very existence of a universe that necessitates thinking about the existence of its Creator, or in other words, God. The universe, or the world of nature, is the subject of scientific study. Indeed, all the branches of physical science focus upon the world of nature.

It is a generally accepted fact that the world of nature cannot be discussed as if it were a journalistic issue. This is true also of God, for God is a scientific subject. Thus, only the scientific method can be applied to the study of God, or the Creator.

Although the existence of God is not a direct area of enquiry in the field of science, it is fully related, albeit indirectly, to the subject of science. Scientific studies have only confirmed that there is a supreme factor behind all the events in our world. Science calls it the law of nature. But this is a matter of nomenclature. If it is given religious nomenclature, another name for this supreme law of nature can be ‘God’. If not directly, then indirectly, God is the greatest finding of science.

In this way, we can discover God by studying His creation.

Source: Leading a Spiritual Life

The Quran says that God is the light of the skies and the earth. This means that the world is entirely an expression of divine attributes. A sensitive heart will see reflections of God in everything that exists here. The entire cosmos is a table spread of divine sustenance.

If faith in God gives someone the sensitivity that true faith in God engenders, he will see God's light everywhere in the universe. When the breeze touches him, He will feel that he is experiencing the touch of God in the softness of the breeze. In the flow of a stream he will see the mercy of God expressing itself. When he hears the chirruping of birds, his heart will witness a soul-stirring tune played on a divine musical instrument. When he smells a fragrant flower, it would be like bathing in divine fragrance.

For a true believer, the entire universe is a table spread of divine sustenance. Every single thing in this world has been made in such a way that on seeing it, a person can draw a lesson. Those who truly love God can experience these divine states.

The Flame-of-the-Forest is a tree that bears amazingly beautiful flowers. When autumn comes and its leaves fall, the tree appears like a dry stick. But then a silent revolution happens. It sprouts brilliantly-hued flowers! What was a dry stick is now laden with stunning flowers. It seems as if God has specially sent His beautiful umbrella for something that was thought to be a useless stick.

This happens so that some servant of God may see it and exclaim, “Lord! I, too, am a Flame-of the-Forest tree. If you want, you can cause beautiful flowers to bloom on me! I am a dried stick. If you want, you can make me green! I am leading a meaningless existence. If you want, You can fill my life with meaningfulness! I am standing on the edge of Hell. If you want, you can admit me into Heaven!”

Source: Man and God