"A Man follows the religion of his friend"
Abu Hurairah, may Allah be pleased with him, narrated that the Messenger of Allah(may the peace and blessings be upon him) said:
"A man follows the religion of his friend, so let one of you look at whom he mixes with.) Mu`ammil one of the narrators has a different wording; look at whom he befriends."
It was narrated by Ahmad, at-Tirmidhi, Abu Dawood and al-Bayhaqi in "The Su`ab Al-Iman." At-Tirmidhi said: it is Hasan Ghareeb, Al-Nawawi said: Its isnaad is saheeh, and was classed as Saheeh by al-Albani.