Introspection is a major source of purification known as Tazkiya. Introspection awakens the human mind, it jolts the human personality, and gives the individual the incentive to reform. Introspection in this way leads one to intellectual and spiritual development.

Let us assume that you were provoked and reacted negatively to a hurting remark from someone. Later you became repentant and engaged in introspection about your reaction. Introspection led you to realize that your behaviour would result in making you a negative personality. Such a result would have a deleterious effect in the life after death. In fact it would render one incapable of entering Paradise.