Are there haram states of the heart, as there are haram acts?

Just as Islamic Fiqh, Islamic Jurisprudence, has its haram or forbidden acts, there are forbidden inner states like jealousy, greed, pride and hypocrisy. The one who is pure is closer to Allah than others, as Allah's Messenger ﷺ said: "Allah does not look at the external outward appearance or the wealth, He looks at your heart and deeds." [Sahih Muslim 2564]

The causes and remedies for the forbidden states are discussed by scholars such as Imam al-Ghazali rahimahullah in his Ihya' 'ulum al-din (The Revival of the Religious Sciences), Imam al-Rabbani rahimahullah in his Maktoobat (Letters), al-Suhrawardi rahimahullah in his 'Awarif al-Ma'arif (The knowledges of the illuminates) and other classic works, which also discuss the inner states. These are the books of Islamic jurisprudence, which deal with the inner state of a Muslim, according to the Prophetic Sunnah. [Keller, The Place of Tasawwuf in Traditional Islamic Sciences]

The Shariah in many Qur'anic verses and Hadith commands one to fear Allah, to have sincerity toward Him, to be so certain in one's knowledge of Allah that one worships Him as if one sees Him, to love the Prophet ﷺ more than any other human being, to show love and respect to all fellow Muslims, to show mercy, and to have many other states of the heart. It likewise forbids us such inward states as envy, malice, pride, arrogance, love of this world, anger for the sake of one's ego, and so on.

If we reflect upon these states, they result in a human change so profound that the Qur'an in many verses terms it as purification: "He has succeeded who purifies himself" [Qur'an, al-A'la 87:14]