There is no doubt that company has its effects, good company makes one good and bad company makes one bad. Therefore, one must always adopt the companionship of pious people.
It is stated in the Glorious Qur’an:
And restrain yourself along with those who pray to their Lord in the morning and evening, seeking His pleasure; and let not your sight fall on anything besides them; desiring the adornment of the life of this world? And do not follow him whose heart We have made neglectful of Our remembrance. (18:28)
The noble Prophet sal Allahu `alayhi wa sallam said:
“A good companion is the one that helps you when you are remembering Him (Allah Almighty) and reminds you when you forget.”
~ Transmitted by Suyuti in al-Jami` us-Saghir (pp. 244 #3999).
“A person is on the religion of his companions. Therefore let every one of you carefully consider the company he keeps.”
~ Transmitted by Tirmidhi.
“The parable of a good friend and a bad friend is that of a carrier of musk and a blacksmith. The carrier of musk will give you some, or you will buy some, or you will notice a good smell; but as for the blacksmith, he will burn your clothes or you will notice a bad smell.”
~ Transmitted by Muslim in as-Sahih.
“A good companion is the one whose sight makes you remember Allah Almighty and whose actions make you remember the afterlife.
~ Transmitted by Suyuti in al-Jami` us-Saghir (pp. 247 #4063).
The Commander of the Faithful `Umar al-Faruq radi Allahu `anh said,
“Do not get involved in something that does not benefit you. Stay away from your enemy, and avoid your friend unless he is trustworthy because no one is like a trustworthy man… seek the advice of people who fear Allah Almighty.
~ Transmitted by al-Muttaqi in Kanz al-`Ummal (9:75 #25565).