"My son, if sinners entice thee, consent thou not....My son, walk not thou in the way with them; refrain thy foot from their path." "Enter not into the path of the wicked, and go not in the way of evil men. Avoid it, pass not by it, turn from it...."
It is far more likely that "birds of a feather, flock together!" The Apostle Paul warned against associating with "the world" but encouraged believers to associate with God and His children; he wrote:
"Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? And what communion hath light with darkness? And what concord hath Christ with Belial? Or what part hath he that believeth with an infidel? And what agreement hath the temple of God with idols? For ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be My people. Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you, and will be a Father unto you, and ye shall be My sons and daughters, saith the Lord Almighty" (2 Cor. 6:14-18).
This may not be true in all cases, but it seems to me that if one associates mostly with non-believers, in order to maintain the relationship, a believer will need to avoid sharing his faith; "the world" wants nothing to do with spiritual things. On the other hand, when believers gather together, they have fellowship with one another because they have their faith in common.
It seems to me that born again believers enjoy spending time with one another; and that is good, because they will be spending eternity with each other and with Jesus Christ. Conversely, unbelievers prefer spending time with each other and that they too will be spending eternity with them; unfortunately, instead of being with God, they will be cast into the Lake of Fire, and will be spending eternity with the Antichrist, the False Prophet, and with Satan and his angels (Rev. 20:10-15)!
Choose your friends wisely; you may be with them for eternity!