Hadith 1:

مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ الْحَسَنِ بْنِ مَحْبُوبٍ عَنْ هِشَامِ بْنِ سَالِمٍ عَنْ زُرَارَةَ قَالَ: قُلْتُ لِأَبِي جَعْفَرٍ ع أَخْبِرْنِي عَنْ مَعْرِفَةِ الْإِمَامِ مِنْكُمْ وَاجِبَةٌ عَلَى‌  جَمِيعِ الْخَلْقِ فَقَالَ إِنَّ اللَّهَ عَزَّ وَ جَلَّ بَعَثَ مُحَمَّداً ص إِلَى النَّاسِ أَجْمَعِينَ رَسُولًا وَ حُجَّةً لِلَّهِ عَلَى جَمِيعِ خَلْقِهِ فِي أَرْضِهِ فَمَنْ آمَنَ بِاللَّهِ وَ بِمُحَمَّدٍ رَسُولِ اللَّهِ وَ اتَّبَعَهُ وَ صَدَّقَهُ فَإِنَّ مَعْرِفَةَ الْإِمَامِ مِنَّا وَاجِبَةٌ عَلَيْهِ وَ مَنْ لَمْ يُؤْمِنْ بِاللَّهِ وَ بِرَسُولِهِ وَ لَمْ يَتَّبِعْهُ وَ لَمْ يُصَدِّقْهُ وَ يَعْرِفْ حَقَّهُمَا فَكَيْفَ يَجِبُ عَلَيْهِ مَعْرِفَةُ الْإِمَامِ وَ هُوَ لَا يُؤْمِنُ بِاللَّهِ وَ رَسُولِهِ وَ يَعْرِفُ حَقَّهُمَا قَالَ قُلْتُ فَمَا تَقُولُ فِيمَنْ يُؤْمِنُ بِاللَّهِ وَ رَسُولِهِ وَ يُصَدِّقُ رَسُولَهُ فِي جَمِيعِ مَا أَنْزَلَ اللَّهُ يَجِبُ عَلَى أُولَئِكَ حَقُّ مَعْرِفَتِكُمْ قَالَ نَعَمْ أَ لَيْسَ هَؤُلَاءِ يَعْرِفُونَ فُلَاناً وَ فُلَاناً قُلْتُ بَلَى قَالَ أَ تَرَى أَنَّ اللَّهَ هُوَ الَّذِي أَوْقَعَ فِي قُلُوبِهِمْ مَعْرِفَةَ هَؤُلَاءِ وَ اللَّهِ مَا أَوْقَعَ ذَلِكَ فِي قُلُوبِهِمْ إِلَّا الشَّيْطَانُ لَا وَ اللَّهِ مَا أَلْهَمَ الْمُؤْمِنِينَ حَقَّنَا إِلَّا اللَّهُ عَزَّ وَ جَلَّ 

Narrated with a chain of trustworthy narrators that from Zurarah, who said, 

I said to Abu Jafar Imam Baqir (عليه السلام), "Inform me, is the knowing (marifat) of the Imam from among you obligatory upon all creation?"

The Imam said, "Indeed, Allah (عز وجل), sent Muhammad (صلى الله عليه وآله) to all people as a messenger and as Allah's proof upon all His creation on earth. So whoever believes in Allah and in Muhammad - the Messenger of Allah (صلى الله عليه وآله), and follows him and considers him truthful, then the knowing of the Imam from among us is obligatory upon him. 

But whoever does not believe in Allah and His Messenger, nor follows him, nor considers him truthful, nor acknowledges their rights, then how can the knowing of the Imam be obligatory upon him when he does not believe in Allah and His Messenger nor acknowledge their rights?"

He (the narrator) said, "Then what do you say about those who believe in Allah and His Messenger and deem His Messenger truthful in all that Allah has revealed – is the right of knowing you obligatory upon those?"

The Imam said, "Yes. Do these people not know so-and-so and so-and-so? (i.e. referring to muslims following other self made caliphs & Imams)" 

I (the narrator) said, "Yes." 

The Imam said, "Do you think that it is Allah who placed the knowledge of those people in their hearts? By Allah, none but Satan placed that in their hearts! And by Allah no one but than Allah (عز وجل) has inspired our rights to the believers."

[Source: al-Kafi, Vol. 1, Pg. 180-181]

Hadith 2:

وَ بِالْإِسْنَادِ الْأَوَّلِ عَنْ زُرْعَةَ، عَنْ أَبِي عَبْدِ اللَّهِ (عَلَيْهِ السَّلَامُ)، قَالَ: قُلْتُ لَهُ: أَيُّ الْأَعْمَالِ هُوَ أَفْضَلُ بَعْدَ الْمَعْرِفَةِ قَالَ: مَا مِنْ شَيْ‌ءٍ بَعْدَ الْمَعْرِفَةِ يَعْدِلُ هَذِهِ الصَّلَاةَ، وَ لَا بَعْدَ الْمَعْرِفَةِ وَ الصَّلَاةِ شَيْ‌ءٌ يَعْدِلُ الزَّكَاةَ، وَ لَا بَعْدَ ذَلِكَ شَيْ‌ءٌ يَعْدِلُ الصَّوْمَ، وَ لَا بَعْدَ ذَلِكَ شَيْ‌ءٌ يَعْدِلُ الْحَجَّ، وَ فَاتِحُةُ ذَلِكَ كُلِّهِ مَعْرِفَتُنَا، وَ خَاتِمَتُهُ مَعْرِفَتُنَا

The narrator says,

I asked Abu Abd-Allah Imam Sadiq (عليه السلام),

"What is the best deed after recognizing [the Imam]?"

The Imam replied,

"There is nothing after recognition that is equal to this prayer [Salat]. 

After recognition and prayer, there is nothing equal to zakat.

Then, after that, nothing is equal to fasting.

And after that, nothing is equal to the hajj pilgrimage.

And the beginning of all this is knowing us, and the end of it is knowing us."

[Source: al-Amali, Shaikh Tusi, Pg. 694]