From Imam Mahdi's (atfs) letter to Shaikh Mufeed:

أَنَّهُ مَنِ اتَّقَى رَبَّهُ مِنْ إِخْوَانِكَ فِي الدِّينِ وَ خَرَجَ عَلَيْهِ بِمَا هُوَ مُسْتَحِقُّهُ‏ كَانَ آمِناً مِنَ الْفِتْنَةِ الْمُظِلَّةِ- وَ مِحَنِهَا الْمُظْلِمَةِ الْمُضِلَّةِ وَ مَنْ بَخِلَ مِنْهُمْ بِمَا أَعَارَهُ اللَّهُ مِنْ نِعْمَتِهِ عَلَى مَنْ أَمَرَهُ بِصِلَتِهِ فَإِنَّهُ يَكُونُ خَاسِراً بِذَلِكَ لِأُولَاهُ وَ آخِرَتِهِ 

وَ لَوْ أَنَّ أَشْيَاعَنَا وَفَّقَهُمُ اللَّهُ لِطَاعَتِهِ عَلَى اجْتِمَاعٍ مِنَ الْقُلُوبِ فِي الْوَفَاءِ بِالْعَهْدِ عَلَيْهِمْ لَمَا تَأَخَّرَ عَنْهُمُ الْيُمْنُ بِلِقَائِنَا وَ لَتَعَجَّلَتْ لَهُمُ السَّعَادَةُ بِمُشَاهَدَتِنَا عَلَى حَقِّ الْمَعْرِفَةِ وَ صِدْقِهَا مِنْهُمْ بِنَا فَمَا يَحْبِسُنَا عَنْهُمْ إِلَّا مَا يَتَّصِلُ بِنَا مِمَّا نَكْرَهُهُ وَ لَا نُؤْثِرُهُ مِنْهُمْ‏ وَ اللَّهُ الْمُسْتَعانُ‏ وَ هُوَ حَسْبُنَا وَ نِعْمَ الْوَكِيلُ‏

"If anyone from your brothers in faith acquires the fear of Allah (Taqwa) and pays that amount, which is obligatory on him to those who are deserving, would be safe from the overshadowing discord (fitnah) and it's dark misguiding trials/suffering.

But if anyone is miserly in giving away the wealth that Allah has loaned to him, he will be in loss due to this in his life and his hereafter."

"If our Shia, may Allah make them successful in His obedience, had been united at hearts in fulfilling the pledge/promise that is upon them, then the blessings of our meeting would not have been delayed from them. And surely happiness would have hastened to them due to seeing Us with the perfect recognition (Marifah) and truthfulness from them (shias).

And we would not be away/hidden from them (shias) but due to what reaches us from them which We dislike and do not like to see from them. And Allah is the helper and He is sufficient for Us and the best protector."

[Source: Bihar al-Anwar, Vol. 53, Pg. 177]