Can thinking be used in religion or not?

‘Thinking’ and ‘reflecting’ have been used in the Quran numerous times. According to the Quran

There are signs in the creation of heavens and the earth, and in the alteration of night and day for people of understanding.(3:190)

The creations of God therefore present all signs for those who think. Thinking leads to reflection, by way of which man can learn the profound truths of life.