How to Soften Your Heart

A believer does not wish for anything more than the pleasure of Allah. The pleasure of Allah is not attained with anything greater than the love for the words of Allah (i.e Quran). And some of the greatest qualities that Allah has praised His pious servants of possessing are 3 qualities.

  

When the verses of Allah are recited upon, they feel :

1) fear and humbleness in their hearts

2) creeping of the skin

3) dropping of tears

Allah mentioned in the Quran [19: 58]

"Those were some of the prophets on whom Allah did bestow His Grace,- of the posterity of Adam, and of those who We carried (in the Ark) with Noah, and of the posterity of Abraham and Israel of those whom We guided and chose. Whenever the Signs of ((Allah)) Most Gracious were rehearsed to them, they would fall down in prostrate adoration and in tears."

"Mereka itulah sebahagian dari Nabi-nabi yang telah dikurniakan Allah nikmat yang melimpah-limpah kepada mereka dari keturunan Nabi Adam, dan dari keturunan orang-orang yang Kami bawa (dalam bahtera) bersama-sama Nabi Nuh, dan dari keturunan Nabi Ibrahim, dan (dari keturunan) Israil- dan mereka itu adalah dari orang-orang yang Kami beri hidayah petunjuk dan Kami pilih. Apabila dibacakan kepada mereka ayat-ayat (Allah) Ar-Rahman, mereka segera sujud serta menangis."

Certain things come with habituation. And the best thing a person can advice another who wants to soften their heart is to stand in front of Allah at night! And that he recites verses where Allah praises or describes Himself. There is no speech more beautiful and has an effect like the verses where Allah praises Himself and informs us about Himself. And there is no one greater than Allah. No speech is greater than the speech of Allah and nobody is more knowledgeable about Allah than Himself. 

So, if you stand in front of Him on the first nights when you first start praying the tahajjud, choose verses where Allah praises Himself. You also need to know the meaning of verses that you recite. And repeat these verses until your heart softens and your eyes cry progressively. After a number of days, you will find that your heart will not find peace in anything more than it does in the remembrance of Allah. The company of Allah can't be compared to the company of His creation.

Allah in the Quran says about Himself [25: 45-47]

"Hast thou not turned thy vision to thy Lord?- How He doth prolong the shadow! If He willed, He could make it stationary! then do We make the sun its guide. Then We draw it in towards Ourselves,- a contraction by easy stages. And He it is Who makes the Night as a Robe for you, and Sleep as Repose, and makes the Day (as it were) a Resurrection"

"Tidakkah engkau melihat kekuasaan Tuhanmu? - bagaimana Ia menjadikan bayang-bayang itu terbentang (luas kawasannya) dan jika Ia kehendaki tentulah Ia menjadikannya tetap (tidak bergerak dan tidak berubah)! Kemudian Kami jadikan matahari sebagai tanda yang menunjukkan perubahan bayang-bayang itu. Kemudian Kami tarik balik bayang-bayang itu kepada Kami, dengan beransur-ansur. Dan Dia lah Tuhan yang menjadikan malam untuk kamu sebagai pakaian, dan menjadikan tidur untuk berhenti rehat, serta menjadikan siang untuk keluar mencari rezeki."

These are things which we can see it happen and when it is linked to its creator, then certainly (faith) increases in the heart! 

Allah also says in Surah Hashr [59: 23-24]

"Allah is He, than Whom there is no other god;- the Sovereign, the Holy One, the Source of Peace (and Perfection), the Guardian of Faith, the Preserver of Safety, the Exalted in Might, the Irresistible, the Supreme: Glory to Allah. (High is He) above the partners they attribute to Him." 

"Dia lah Allah, yang tidak ada Tuhan melainkan Dia; Yang Menguasai (sekalian alam); Yang Maha Suci; Yang Maha Selamat Sejahtera (dari segala kekurangan); Yang Maha Melimpahkan Keamanan; Yang Maha Pengawal serta Pengawas; Yang Maha Kuasa; Yang Maha Kuat (menundukkan segala-galanya); Yang Melengkapi segala KebesaranNya. Maha Suci Allah dari segala yang mereka sekutukan denganNya."

"He is Allah, the Creator, the Evolver, the Bestower of Forms (or Colours). To Him belong the Most Beautiful Names: whatever is in the heavens and on earth, doth declare His Praises and Glory: and He is the Exalted in Might, the Wise."

"Dia lah Allah, Yang Menciptakan sekalian makhluk; Yang Mengadakan (dari tiada kepada ada); Yang Membentuk rupa (makhluk-makhlukNya menurut yang dikehendakiNya); bagiNyalah nama-nama yang sebaik-baiknya dan semulia-mulianya; bertasbih kepadaNya segala yang ada di langit dan di bumi; dan Dialah Yang tiada bandingNya, lagi Maha Bijaksana."

This is the speech of Allah, the most powerful about Himself. This is the food which the heart of the believer survives by. This is what leads to the pleasure of Allah and His gardens and guides the believer to good deeds. 

p/s : Don't just read it, try it insyaAllah it'll work..