Hadith 1:

نحن الخزان لدين الله، ونحن مصابيح العلم، إذا مضى منا علم بدا علم، لا يضل من اتبعنا ولا يهتدي من أنكرنا ولا ينجو من أعان علينا عدونا، ولا يعان من أسلمنا

فلا تتخلفوا عنا لطمع دنيا وحطام زائل عنكم وأنتم تزولون عنه، فإن من آثر الدنيا على الآخرة واختارها علينا عظمت حسرته غدا. وذلك قول الله عز وجل "أَنْ تَقُولَ نَفْسٌ يَا حَسْرَتَى عَلَى مَا فَرَّطْتُ فِي جَنْبِ اللهِ وَإِنْ كُنْتُ لَمِنَ السَّاخِرِينَ

Narrated from Imam Sadiq (عليه السلام) that Imam Ali (عليه السلام) said as part of a long narration:

"We are the reservoir of Allah's religion, and We are the lamps of knowledge. When one authority/guide-post passes away from among us, then another rises (i.e. one Imam after another).

Those who follow Us will not be misled, and those who deny Us will not be guided, and those who help Our enemy against Us will not be saved, and those who leave/desert/forsake Us will not be helped.

"So do not stay away from Us because of the hope of this world and the vanities of this world that will go away from you while you are going away from it. For whoever prefers this world to the hereafter and chooses the world over Us, his grief will be great tomorrow (Qayamat). And that is the saying of Allah (عز و جل), "Lest a soul should say, "Oh, [how great is] my regret over what I neglected in regard to Allah and that I was among those who mocked." (39:56)

[Source: al-Khisaal, Shaikh Saduq, Ch.27, Hadith.1]