How can I have a pure heart, and what should I do?

A white heart is a sound heart, free from every doubt or desire that contradicts Allah Almighty's command. It is free from polytheism (shirk) and hypocrisy, malice, hatred, envy, innovations (bid'ah), and superstitions. It is a heart that is free from every will that contradicts the will of Allah Almighty, and it has not been afflicted with hardness. Allah Almighty says: "The Day when neither wealth nor sons will benefit, but only he who comes to Allah with a sound heart." (Ash-Shu'ara: 88-89).

Sheikh Ibn As-Sa'di explained that a sound heart is one that is free from polytheism and doubt, from loving evil and persisting in innovation and sins, and is characterized by sincerity, knowledge, certainty, and love of good.

Also, a white heart is one that rejects temptations, denounces them, and flees from them. Thus, faith shines brightly within it, making it white and luminous, as the Prophet, peace and blessings be upon him, described the hearts of people.

To achieve this, one must avoid sin, transgression, malice, and envy, adhere to Allah's obligations, and increase in supererogatory acts of worship. One must strive against oneself to obey Allah and His Messenger, associate with the righteous, seek religious knowledge, constantly engage in remembrance (dhikr) and glorification (tasbeeh), recite the Qur'an with contemplation, and frequently supplicate to Allah to grant you a sound, white heart.