Fitra
Fitra is an Islamic belief that every person is born good, with a tendency towards goodness and aversion towards evil.For example, cheating, lying, deceiving, stealing, backbiting, harming others are evil and sinful acts that every human knows. We are born with those senses. We didn't need to learn those through our lives.
Our souls came to this earth pure, full of light. But through our lives, if we engage in sinful acts, our soul, our light starts diminishing, and darkness runs over it.
But the light is always there. It is like, light in a glass, but you can't see the light through glass since it is dirty. Deep down inside, a person knows those things are wrong.