Primitive Apostolic Christianity
Roman Catholicism, Orthodox Christianity, as well as many other denominations consider themselves to be Apostolic, meaning they believe that they are based on the teachings and traditions that Jesus gave his Twelve Apostles (for example the Great Commission), and which they say they then handed down to the next generation of Christians.
The label Primitive and Apostolic, in terms of Christianity, are used by such authors as Alan Knight, Primitive Christianity in Crisis, and Roderick Meredith, Restoring Apostolic Christianity, to describe Christians, who are sometimes called Jewish Christians, although the term is not completely descriptive of all who follow Primitive Apostolic Christian doctrine.
Some Christian sects today view these "Primitive Apostolic teachings" and observances as the proper form of Christianity. The collection of non-biblical, pre-Nicene writings is called by some the Ante-Nicene Fathers. These groups often see the verses in Acts 15:19-21 as a directive from the first Council of Jerusalem, also called the Apostolic Decree, to observe the basic understanding of the Noahide Laws in order to be considered righteous Gentiles, and not be required to live completely as Torah-observant Jews. This settled a dispute among the first Christians, which began as a sect of first century Judaism, as to whether the new Gentile converts were required to become circumcised and live completely under the dictates of Judaism (Acts 15:5,24). The Noahide Law was based on the understanding that some ordinances were in effect at least since the time of Noah, and some had been given in the Garden of Eden to Adam and Eve, thus given to all mankind.
Judaism has continued to observe Gentiles, even when they become proselytes, as not being under the same scrutiny of the ordinances of Judaism. They may have a part in salvation and in the world to come just by observing the Noahide Law according to Maimonides, who was a Jewish scholar of the thirteenth century. There is much speculation, and some disagreement as to what is part of the Noahide Law, even among Jewish scholars (see Noahide Laws for more information on the Jewish perspective).
Some groups consider themselves unique in current observation of Primitive Apostolic Christianity. These include most Sabbatarian Church of God, and some Noahide Nazarenes. The doctrines vary slightly from each group, but usually include the teaching that the Sabbath was one of the observances given to Adam and Eve, as well as the Sacred Calendar, in order to count the years, seasons, weeks and days. They claim that there is evidence that events such as Abraham's offering of his son Isaac, occurred at the time of the Passover, therefore the High Sabbaths are included in the covenant that Noah is said to have observed. Also related is Quartodecimanism. Clean and unclean animals were also understood in the time of Noah, as can be seen in Genesis 7:2. These precepts are viewed to be included in the Noahide Law, and along with the Ten Commandments given to Moses, to be observed by true Christians. The Sermon on the Mount (Matthew 5-7) is also specific regarding Antinomianism, which is the rejection of biblical teachings concerning observance of the Law.
Mormons also consider themselves unique in current observation of Primitive Apostolic Christianity, but with current revelation given priority. That is, the "latter-day" saints' teachings are primary for understanding. They believe that Christianity lost its priesthood authority sometime before the Council of Nicaea in 325, but that it was restored to Joseph Smith, founder of the Church of Jesus Christ of Latter-day Saints. The primitive observances are relegated to secondary status in observance of progressive revelation, much as mainstream Christianity is said-to-have changed the appointed times such as fourth commandment obedience.