The Love for the Ahl ul-Bayt (A.S.) is Obligatory on Everybody

In His Book, God makes obligatory on everybody to love the Prophet's household as the wage for his conveying the divine mission, and makes it one of his rights:
"(Muhammad), say, "I do not ask you for any payment for my preaching to you except (your) love of (my near) relatives." Whoever achieves virtue will have its merit increased. Allah is All-forgiving and Appreciating. (42:23)"
the Ahl ul-Bayt (a) are characterized by all qualities of admiration and incentives of love and loyalty. They are the choice people, the arguments against the creatures, the ships of salvation, and -preceded by their father the Prophet (s)- the best of everyone who ever lived on this earth in lineage, value, merits, and glories.
It is impossible for the sound conscience to accept to love the Prophet (s) apart from his immaculate family who are worthy of the best concepts of love. To love the Prophet (s), but not his immaculate family, is falsity originated from hypocrisy and meanness.
Abdullah ibn Mas'oud narrated:
One day, we were accompanying the Prophet (s) in one of his journeys when a Beduin with an orotund voice shouted at us, "Mohammed!" "What do you want?" answered the Prophet (s). "What is it if an individual loves a people but he does not imitate them in deeds?" asked the Beduin. "One will be attached to the one he loves," replied the Prophet (s). "Mohammed," shouted the Beduin, "Call me to Islam." The Prophet (s) said: "You should declare that there is no god but Allah and that I am the Messenger of Allah, offer the prayer, defray the zakat, fast during the month of Ramadan, and perform the hajj to the Holy House."
"Mohammed," asked the Beduin, "Do you ask for wage for so?" "No," replied the Prophet (s), "I do not take any wage except that you must regard the relatives." "Whose relatives? Mine or yours?" asked the Beduin. "It is my relatives," answered the Prophet (s). The Beduin said: "Give me your hand so that I will declare allegiance to you. No good is expected from him who loves you, but not your relatives."( Quoted from Bihar ul-Anwar; 7/389 (as quoted from Sheikh al-Mufid's al-majalis).
The Imamite Shia have agreed unanimously on the fact that the Immaculate Imams of the Ahl ul-Bayt (a) are the intendeds in the Verse:
"(Muhammad), say, "I do not ask you for any payment for my preaching to you except (your) love of (my near) relatives." Whoever achieves virtue will have its merit increased. Allah is All-forgiving and Appreciating. (42:23)"
A good number of great exegesists and traditionists of the other sects of Islam, such as Ahmed ibn Hanbal, at-Tabarani, and al-Hakim (as quoting the opinion of ibn Abbas) agreed with the Shia on this fact.
Ibn Hagar, in Chapter One of Section Eleven of as-Sawaaiq ul-Muhriqa, narrates the following:
When the Verse (intended) was revealed, they asked: "God's Messenger, who are your relatives whom we must love and regard?" The Prophet (s) answered: "They are Ali, Fatima, and their two sons." (For more, refer to Sharafuddin's al-kalimat ul-Gharraa fi Tafdheel iz-Zahraa, 18).
Consider how the Prophet (s) urged people to regard his family through the aforementioned narration. However, many texts concerning the Prophet's assertion on the obligatory love and regard for his relatives are related by the two majors schools of Islam -i.e. Shia and Sunna-.
Regarding the Shia, let us cite the following narrations:
On the authority of his fathers, Imam as-Sadiq narrated that the Prophet (s) said: "He who loves us-the Ahl ul-Bayt should thank Allah for the foremost grace. It is the legal birth. Only will the legal sons love us." (Quoted from Bihar ul-Anwar; vol. 7 page 389 (as quoted from Ilal ush-Sharayi, Meaani al-Akhbar, and al-Amali).
Imam al-Baqir narrated on the authority of his father and grandfather that the Prophet (s) said: "The love for my household and me will help in seven situations whose horrors are enormous: at death, in the grave, in the Resurrection, in the Recorded Account, in the Judgment, in the Balance, and on the Path." (Quoted from Bihar ul-Anwar; vol. 7 page 391 (as quoted from al-khissal).
"Any servant who worships Allah for one thousand years and then is slaughtered (wrongfully) like a sheep, but he attends before Allah bearing malice against us-the Ahl ul-Bayt, Allah will certainly reject all his acts of worship." (Quoted from Bihar ul-Anwar; 7/397 (as quoted from al-Barqi's al-Mahassin).
"On the Day of Resurrection, a servant's feet will not move before he is asked about four matters: He will be asked how he had spent the age of his youth, how he had finished his age, what earnings he had got and where from he had got them and how he had spent them, and he will be also asked about his affection to us-the Ahl ul-Bayt." (Quoted from Bihar ul-Anwar; 7/389 (as quoted from Sheikh al-Mufid's al-majalis).
Al-Hakam ibn Utaiba related the following:
I was with Imam al-Baqir (a) in his house, which was suffocated by his people when an old man came leaning on a stick. As he stopped at the door of the house, he said: "Peace and Allah's mercy and blessings be upon you, son of God's Messenger." Abu Ja'far (a) replied: "Peace and Allah's mercy and blessings be upon you, too." The old man turned his face to the others and said: "Peace be upon you," and each one answered him. He then turned his face towards Imam al-Baqir (a) and said:
"Son of God's Messenger, let me approach you, God may make me your sacrifice. By God I swear, I do love you and love everyone who loves you. By God I swear, my love for you and my love for him who loves you is not purposed for a worldly desire. I also hate and disavow your enemy. By God I swear, my hatred and disavowal of your enemy is not for a previous personal enmity between him and me. By God I swear, I deem lawful all that which you decide as lawful, deem unlawful all that which you decide as unlawful, and expect your Affair. Do you -may God make me your sacrifice- accept me, then?"
Having heard these words, Imam al-Baqir (a) said to him: "Come to me, come to me."
When the man sat next to him, the Imam (a) said: "Old man, my father Ali ibn al-Hussein (a), once, was visited by a man who asked him the same question that you have just put. My father's answer was, 'If you die bearing these beliefs, you will be received by the Messenger of Allah, Ali, al-Hasan, al-Hussein, and Ali ibn al-Hussein (a), and you will be pleased, delighted, and cheerful. And when your soul reaches your mouth -i.e. about to depart your body-, you will be greeted with rest and happiness by the Honorable Recording Angels. And if you live, Allah will show you delighted things, and you will be with us on the Highest Peak… etc. (Quoted from al-wafi; part 3 page 139 (as quoted from al-kafi).
Regarding narrations that are recorded in the reference books of our Sunni brothers, we cite the following as examples:
Ibn Hanbal and at-Tirmithi, as recorded in as-Sawaaiq ul-Muhriqa; page 91, narrated the following:
The Prophet (s), once, took al-Hasan and al-Hussein from the hands and said: "He who loves me, these two, their father, and their mother will stand in a rank as same as mine on the Day of Resurrection."( Quoted from Imam Sharafuddin's al-Fussoul ul-Muhimma; page 41).
Ibn Abbas narrated that the Prophet (s), once, looked in the face of Ali (a) and said: "You are sayyid in this world as well as the world to come. Your disciple is my disciple, and my disciple is Allah's disciple. And your enemy is my enemy, and my enemy is Allah's enemy. Woe unto him who will hate you after my departure."( Quoted from Fadhaail ul-Khamsa min as-Sihah is-Sitta; part 1 page 200. (In the book titled al-Mustadrak ala as-sahihayn; part 3 page 127, this narration is recorded).
In his book titled Kitab ul-Wilaya, At-Tabari records the following:
Ali (a) said: "Three persons will never love me: the bastards, the hypocrites, and those whom were composed during their mothers' periods of menstruation."
At-Tabarani, in his book titled al-Mu'jam ul-Awsat, as-Suyouti, in his book titled Ihyaa ul-Meyt, and ibn Hagar, in his as-Sawaaiq ul-Muhriqa; Chapter: Urging on the love for the Ahl ul-Bayt, recorded the following hadith:
The Prophet (s) said: "Cling to the love for us-the Ahl ul-Bayt, for anyone who meets Allah bearing love for us will be in Paradise due to our Right of Intercession. I swear by Him Who prevails on my soul, unless our right is recognized, none's deed will be useful (for him)."( Quoted from Sharafuddin's al-Muraja'at; page 22).
The term of the Ahl ul-Bayt includes the twelve sinless Imams (a), because such lofty characteristics are deserved by no one at all except them, since they are the representatives of God and the auspicious successors of the Prophet (s).