“And have no fellowship with the unfruitful works of darkness, but rather reprove them.”Ephesians 5:11.
(OHC 256.1)
The Christian should withdraw himself from the company of those who are as a snare to his soul. When you come in contact with those whom you cannot lift into a pure and holy atmosphere, because their moral tastes are wholly perverted, you must shun their society. Persons of this class have generally a strong will and positive temperament, and when wrought upon by the enemy of God, they become efficient agents in leading souls from the path of righteousness to paths that are false and dangerous. The moral atmosphere surrounding these souls is tainted with evil, and exerts only a defiling influence.
(OHC 256.2)
Your associates may not be expected to be free from imperfections or sin. But in choosing your friends, you should place your standard as high as possible. The tone of your morals is estimated by the associates you choose. You should avoid contracting an intimate friendship with those whose example you would not choose to imitate....
(OHC 256.3)
Choose for your associates those who hold religion and its practical influences in high respect. Keep the future life constantly in view. Let not your associations put these thoughts out of your mind. Nothing will so effectually banish serious impressions as intercourse with the vain, careless, and irreligious. Whatever intellectual greatness such persons may attain, if they treat religion with levity or even with indifference, they should not be your chosen friends. The more engaging their manners in other respects, the more should you dread their influence as companions, because they would throw around you an irreligious, godless, irreverent influence and yet combine it with so many attractions that it is positively dangerous to morals.
(OHC 256.4)
Dare to be a Daniel. Dare to stand alone.... A cowardly and silent reserve before evil associates, while you listen to their devices, makes you one with them.... Have courage to do right.
(OHC 256.5)