It was narrated that 'Abdullah bin Mas'ood (رضي الله عنه) said:

A man said to The Messenger of Allah (ﷺ): How can I know whether I am doing good or bad? The Prophet (ﷺ) said: “If you hear your neighbours saying that you have done good, then you have done good, and if you hear them saying that you have done bad, then you have done bad.”