Imam Hussain (A.S.) is the Beloved of Allah (SWT)

During the reign of Mutawakkil, Imam Ali al-Naqi (A.S.) felt very ill for some time; the Imam knew his cure would be in the pilgrimage to the shrine of Imam Hussain (A.S.). Thereupon he asked his companions to select a group of people and send them to Karbala at the Imam's expense. There the selected group would pray for the Imam and ask Allah (SWT) for his health to return.
Companions of Imam Ali al-Naqi (A.S.) discussed the matter with each other and returned to the Imam saying: "O son of Allah's messenger! Your status is better than that of Karbala's, because you are the Imam of the time, Allah's live deputy, and the best of mankind on earth. Your prayer is certainly answered. How will our prayer in Karbala have any affect upon you?"
The Imam calmly replied: "There are positions for Allah in the matter, in that He prefers for worship to be done there. Although the status of the Messenger of Allah (S.A.W.) was higher than the Ka'ba and the black stone, yet the Prophet would still circumambulate the Ka'ba and the black stone. There are certain places that if one prays, Allah will accept and answer his prayers. The shrine of Hussain is therefore the same."
Imam Hussain (A.S.) is the beloved of Allah (SWT) who sacrificed his life, children, family, and friends in the way of Allah (SWT). In this mission he accepted all calamities that faced him, to save the religion of Allah (SWT). For this reason, he holds a special place in the presence of Allah (SWT).

(Selection taken from the book "With Ahl al-Bayt (A.S.)", by Sayyed Taqi Waredi)