"Now I urge you, brethren, note those who cause divisions and offenses, contrary to the doctrine which you learned, and avoid them." (Romans 16:17)
The Scripture above admonishes us to take note of and avoid those who cause division and offenses contrary to the doctrine of Christ. You've been taught the love of Christ, you've been indoctrinated with the Word of God in a certain direction-- continue in the Word. Mark and avoid those who live contrary to the truth of the Gospel, the truth that you've been taught. This is God's instruction. It's the same warning He gave through the Apostle Paul to the Philippian church. He said:
"Beware of dogs, beware of evil workers, beware of the mutilation!"
Here he was referring to those who stir up mischief in the Church.
These could be people in the same local church, small group, neighborhood, etc. and they're Christians. God wouldn't warn you about them if He didn't think your association with them would be harmful to your Christian walk. Many have found themselves in serious trouble with the wrong people. The Lord's admonition is clear: you're to "mark" and "avoid" mischief makers, not to try and change them. Don't keep company with people who deliberately don't walk in love, people who engender disunity in the Church; divisive elements who mislead others.
People get messed up when they get involved with a messed up person.
(1 Corinthians 15:33)
"Do not be misled: 'Bad company corrupts good character.'”
If you've had, or have had friends with whom you're not experiencing any meaningful spiritual progress, or whose friendship hinders your effectiveness in the Gospel, it's time for you to give up such friendships. Don't negotiate-- just end it so that your participation in the faith-- your Christian life-- will be effectual as it should be. Glory to God!
Dear Father, thank You, for Your Word is profitable for doctrine, for reproof, for correction, and for instruction in righteousness. Through the Word, I'm trained and cultured in the godly life and ways of doing things. I'm filled with thoughts of righteousness, and walk in the path of righteousness, which you prearranged for me, in Jesus' Name. Amen.
Further Study: Romans 16:17-18; 2 Timothy 3:2-5 AMPC