Shaykh ‘Abdullaah ‘Azzaam said:
“A group of friends are all like each other, and the longer the friendship lasts, the closer the character and manners of each person in the group will be to the others. Do not believe that a good person can live for long with a corrupt person, unless the corrupt person improves and follows the example of the good person.
This is why you should look for the good people, and a friend is like a chain: he will either drag you into Paradise, or drag you into Hell. He will either cause you problems or he will help you solve your problems.”
[At-Tarbiyyah Al-Jihaadiyyah Wal-Bina, 5/35]