Volume 3, Book 34, Number 314:
Narrated Abu Musa (radiallaahu `anhu):
Allah’s Apostle (sallallaahu `alayhi wasallam) said, “The example of a good companion (who sits with you) in comparison with a bad one, is I like that of the musk seller and the blacksmith’s bellows (or furnace); from the first you would either buy musk or enjoy its good smell while the bellows would either burn your clothes or your house, or you get a bad nasty smell thereof.”
Be very careful while choosing your friends because they play an important role in making the future you. You will be influenced by them, willingly or unwillingly. So favor the perfume-seller over the blacksmith.
Having bad friends can not only have adverse effects on your life in this world, it can sabotage your eternal bliss in the Hereafter as well. Why would you want to risk that?
وَيَوْمَ يَعَضُّ الظَّالِمُ عَلَىٰ يَدَيْهِ يَقُولُ يَا لَيْتَنِي اتَّخَذْتُ مَعَ الرَّسُولِ سَبِيلًا
يَا وَيْلَتَىٰ لَيْتَنِي لَمْ أَتَّخِذْ فُلَانًا خَلِيلًا
لَّقَدْ أَضَلَّنِي عَنِ الذِّكْرِ بَعْدَ إِذْ جَاءَنِي ۗ وَكَانَ الشَّيْطَانُ لِلْإِنسَانِ خَذُولًا
“And the Day the wrongdoer will bite on his hands [in regret] he will say, “Oh, I wish I had taken with the Messenger a way.
Oh, woe to me! I wish I had not taken that one as a friend.
He led me away from the remembrance after it had come to me. And ever is Satan, to man, a deserter.”