There are many Christians today who imagine that it is unloving and un-Christian to engage in polemics. Polemics are theological warfare, the practice of opposing, exposing and refuting false teaching.
There are other who imagine that heretics and heresies no longer exist. Heretics, false brethren, false teachers, deceivers and false gospels are only theoretical. This would mean that after centuries of struggle with false doctrine the church can relax. No new threats are on the horizon. The warnings of apostasy can be safely ignored.
Others believe that it is wrong to name false teachers.
None of these views is biblical. The minister has the calling to oppose lies out of the love of the truth. Below is a survey of the New Testament. Other passages could be added.