On the authority of Abu Dharr Jundub ibn Junadah, and Abu Abdur-Rahman Muadh bin Jabal (may Allah be pleased with them), that the Messenger of Allah (peace and blessings of Allah be upon him) said:

Have Taqwa (fear) of Allah wherever you may be, and follow up a bad deed with a good deed which will wipe it out, and behave well towards the people. It was related by at-Tirmidhi, who said it was a Hasan (good) Hadeeth, and in some copies it is stated to be a Hasan Saheeh hadeeth.

It was narrated by Ahmad and at-Tirmidhi and Abu Dawood on the authority of Abu Dharr. It was narrated by Ahmad and at-Tirmidhi on the authority of Mu'adh ibn Jabal. It is classed as Hasan by al-Albani.

This commandment combines the rights of Allah, and the rights of his slaves, the right of Allah on His slaves is to fear him properly.
Piety is the commandment of Allah to the first and the last nations.

The origin of piety is that the slave protects himself from the wrath of Allah by following his orders and avoiding what he prohibited, being mindful of him in secret and in public, fearing his sins and repenting from them always; Allah deserves to be feared of, glorified in the breasts of his slaves until they worship and obey him out of love and satisfaction.

People vary concerning piety, such as their differences in the abilities, some of them restricts himself to doing the recommended matters and avoiding the prohibited and disliked matters, yet others may leave the lawful matters lest they fall in some prohibited matters. Few people may abstain from the worldly pleasures and suffices himself with what keeps him at subsistence level and cover the nakedness that must be covered. However, piety combines all of that.