The Holy Prophet (S) said: "Train your children in three things: the love of your Prophet, the love of his progeny, i.e. Ahlul Bayt, and recitation of the Qur'an."
Al-Jami'-ul-Saghir, vol. 1, p. 14
Imam as-Sadiq (‘a) said: "He who is not able to do any good unto us (Ahlul Bayt) then he may do good to our pious adherents; and he who is not able to visit us, he may visit our righteous followers by which the reward of visiting us (pilgrimage) will be recorded for him."
Bihar-ul-Anwar, vol. 74, p. 354
Imam al-Baqir (‘a) said: "The best means by which servants can obtain nearness to Allah, Mighty and Glorious, is the obedience to Allah, the obedience to His Messenger, and the obedience to those charged with (spiritual) authority."
Then, he (‘a) added: "The love of us (Ahlul Bayt) is Faith and the hatred of us is infidelity."
Al-Kafi, vol. 1, p. 187
Imam as-Sadiq (‘a) said: "Verily, there are various degrees of serving Allah, but affection (and cordial inclination) for us, Ahlul Bayt, is the highest one."
Bihar-ul-Anwar, vol. 27, p. 91