The Prophet (sal Allahu alaihi wa sallam) taught us to ask Allah: “O Allah! Make my heart such that it hopes only from You and remove from it any expectations from anyone other than You, so that I don’t hope for anything from anyone other than You.” [Tareekh al-Khulafa lil-Suyooti]
“Allah” is a personal pronoun which means “that entity which possesses all the perfect attributes and is free of all defects.”
I should work on my heart so that it hopes for good only from Allah (azza wa-jal) and fears none but Him. To obtain this blessing, Allah’s Messenger (sal Allahu alaihi wa sallam) taught us the above mentioned Dua.
When I am convinced that Allah is my owner, the only solver of my problems, the only one who can relieve me of my worries, then will I be able to worship Him as is His right to be worshipped. When I have given Allah my heart, then I can expect from Him that He will free me from dependence on any other than Him, and my calling on Him will not be rejected.
Umar bin al-Khattab (radi Allahu anhu) was one such person who when he invoked Allah’s name what we call “miracles” happened. While Umar was the Khalifa, the king of the Roman Empire, Caesar, sent him a letter saying he was besieged by headaches and requesting him for a cure.
Umar (radi Allahu anhu) sent him his cap and told him that keeping it on his head would make the pain go away. So whenever Caesar would have the cap on his head the pain would go away but when he would take it off the headache would return.
He was very surprised, so out of curiosity he ripped the cap open. He found a piece of paper in it that had “Bismillah ar-Rahmaan ar-Raheem” (In the name of Allah, the Most Beneficent, the Most Merciful) written on it. This deeply affected him, and he said: “Islam is such an exalted religion that a single Ayat of it is a cause for cure; then why shouldn’t the whole religion be a source of salvation?!” And he became a Muslim. [Tafseer al-Kabeer by Imaam Fakhruddin al-Raazi]