Advice of Sufyan Al-Thawree (rahimahullah) to Alee ibn Al-Hasan As-Sulamee:

Your companion should be the one who prevents you from being preoccupied with things of the worldly life that will divert you from Allaah, and one who makes you desire and work for the Hereafter.

Beware of accompanying people who make the dunyah their goal, those who are engrossed in speaking about the worldly life; indeed they will corrupt your religion and your heart.

Remember death much, and seek a lot of forgiveness from what has passed of your sins, and ask Allah for safety for what remains of your life.

Hilyatul Awliyaa Vol. 7 Pg. 82