The innate nature of God-consciousness and goodness that all human beings are created with. 

One of the defining qualities of humanity, according to Islam, is fiṭrah

Everyone is born with a pure soul and an innate attraction to God. We crave connection with our creator and understand His oneness (tawḥīd) at a fundamental level. In some cases, a person’s fiṭrah may become clouded by the events of life. In other cases, the natural inclination of a person’s fiṭrah brings them towards Islam, even when they were not born into it. 

This is why those joining Islam are sometimes referred to as ‘reverts’ rather than converts. Upon taking the shahada (declaration of faith), a person reverts to the state of spiritual purity they exhibited at birth.