If we see a fellow Christian wander from the truth/the doctrines of the Christian faith and/or the moral responsibilities from God's Word, we should try to bring that person back into fellowship with Christ. Point them back to the Truth! If you do that, you'll save them from death/destruction and they will be forgiven. That's true love! Restoring love! "Above all, love each other deeply, because love covers over a multitude of sins." (1 Peter 4:8)
If you see a brother or sister in Christ living in sin or believing in false teaching but you don't say anything to him/her or don't try to turn them from the error of their way, that's not love. Pray for them and pray for God's wisdom and guidance to show you how to bring them back. Speak the truth in love and with grace, respect, and gentleness but by all means, speak God's truth! Don't ever sacrifice the truth on the altar of "grace", political correctness, or fear of being labeled "judgmental" or narrow-minded or preachy. Don't ever minimize the seriousness of sin (our need for repentance). If you truly love them, you'll care about their spiritual well-being/the condition of their soul and you'll do all you can to rescue them.
If you see a brother or sister in Christ living in sin or believing in false teaching but you don't say anything to him/her or don't try to turn them from the error of their way, that's not love. Pray for them and pray for God's wisdom and guidance to show you how to bring them back. Speak the truth in love and with grace, respect, and gentleness but by all means, speak God's truth! Don't ever sacrifice the truth on the altar of "grace", political correctness, or fear of being labeled "judgmental" or narrow-minded or preachy. Don't ever minimize the seriousness of sin (our need for repentance). If you truly love them, you'll care about their spiritual well-being/the condition of their soul and you'll do all you can to rescue them.