On the authority of Abu Hurayrah (may Allah be pleased with him), that the Prophet (peace be upon him) said:

Whoever removes a worldly grief from a believer, Allah will remove from him one of the griefs of the Day of Resurrection. And whoever alleviates the need of a needy person, Allah will alleviate his needs in this world and the Hereafter. Whoever shields [or hides the misdeeds of] a Muslim, Allah will shield him in this world and the Hereafter. And Allah will aid His slave so long as he aids his brother. And whoever follows a path to seek knowledge therein, Allah will make easy for him a path to Paradise. No people gather together in one of the Houses of Allah, reciting the Book of Allah and studying it among themselves, except that sakeenah (tranquility) descends upon them, and mercy envelops them, and the angels surround them, and Allah mentions them amongst those who are with Him. And whoever is slowed down by his actions, will not be hastened forward by his lineage.

[Muslim]