Belgic Confession Articles 17-19 deal with fundamentally important Christian doctrine, who Christ is and what He came to do for salvation.
Polemics
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.
Introducing Our Canons of Dordt Class (available for download)
In 1618-1619 in the Dutch city of Dordrecht a synod met to discuss, and ultimately to condemn, the Arminian heresy, which had been spreading like a leaven throughout the churches in the Netherlands.
The fruit of this Synod of Dordt, at which not only Dutch, but also many foreign delegates were present, was the beautiful creed, the Canons of Dordt.
You Don't Believe in Free Will?!
No Such Thing As The Perfect Church ...
"But there is no such thing as a perfect church!"
Let's face it, churches in Europe, and in Ireland in particular are very weak. Many of them are false. Many of them teach false doctrine. Many of them teach confusing mixtures of doctrine. Many of them teach no doctrine at all. In many of them the sacraments are corrupted, and there has been no church discipline for generations.
Few deny this charge who look objectively and dispassionately at the situation.