What important principles are taught in the following articles of the Church Order of Dordt?

Article 17

Among ministers of the Word, equality shall be maintained with respect to the duties of their office and also in other matters as far as possible according to the judgment of the consistory, and if necessary, of the classis; which equality shall also be maintained in the case of the elders and deacons.

Article 21

The consistories everywhere shall see to it that there are good Christian school teachers, not only to teach the children reading, writing, languages, and the liberal arts, but also to instruct them in godliness and in the catechism.

Article 22

The elders shall be chosen by the judgment of the consistory and the deacons, so that every church shall be at liberty, according to its circumstances, to present to the congregation as many elders as are needed, that they may be installed with public prayers and stipulations after being approved by and with the assent of the congregation, unless any obstacle arise; or twice the number of elders needed may be present, half of them to be chosen by the congregation, and installed in office in the same manner, according to the form for this purpose.

Article 44

The classis shall authorize a number of its ministers, at least two of the oldest, most experienced and competent ones, to visit all the churches once a year, in cities as well as in rural districts, and to take heed whether the ministers, consistories, and school teachers faithfully perform the duties of their offices, adhere to sound doctrine, observe in all things the adopted order, and properly promote as much as lies in them, by word and deed, the edification of the congregation including the youth, to the end that they may in time fraternally admonish those who have in anything been negligent, and may by their advice and assistance help direct all things unto peace, upbuilding, and greatest profit of the churches and schools. And each classis may continue these visitors in service as long as it sees fit, except where the visitors themselves request to be released for reasons of which the classis shall judge.

Article 67

The churches shall observe, in addition to Sunday, also Christmas, Easter, and Pentecost, with the following days, and whereas in most of the cities and provinces of the Netherlands the day of circumcision and of the ascension of Christ are also observed,