Christianity in the ante-Nicene period was the period in Christian history following the Apostolic Age (1st century AD) up to the First Council of Nicaea (325 AD). Although the use of the term Christian () is attested in the Acts of the Apostles (80–90 AD), the earliest recorded use of the term Christianity () is attested by the ante-Nicene Father and theologian Ignatius of Antioch ().Walter Bauer, Greek-English LexiconIgnatius of Antioch Letter to the Magnesians 10, Letter to the Romans (Roberts-Donaldson tr., Lightfoot tr., Greek text)

While the Jewish–Christian community was centered in Jerusalem in the 1st century AD, Gentile Christianity spread widely in the 2nd century AD. One stream of Gentile Christianity (so-called "proto-Orthodox Christianity") that emerged in this period in the persons and theological positions of the Apostolic Fathers would eventually become the international Great Church. Proto-Orthodox Christianity placed importance on the sacrifice of Jesus on the cross as saving humanity, and described Jesus as the incarnated Son of God come to Earth. The 2nd and 3rd centuries AD saw a sharp separation between Jewish Christianity and Pauline or Gentile Christianity, with the latter being derived from the teachings of the Apostle Paul. There was an explicit rejection of Second Temple Judaism and Jewish culture by the end of the 2nd century, with a growing body of anti-Jewish Christian literature. Many doctrinal variations in this era defy neat categorizations, as various forms of Christianity interacted in a complex fashion.

A third major school of thought was Marcionite Christianity, a dualistic theological system that originated with the teachings of Marcion of Sinope in 2nd-century Rome115 years and 6 months from the crucifixion of Jesus, according to Tertullian's reckoning in the apologetical treatise Adversus Marcionem, XV. and held that the Hebrew God of the Old Testament ruled upon the Jews by enslaving them to follow the Mosaic Law, while the Gentiles were saved through divine grace by the Gospel of Jesus Christ, sent by an entirely different Supreme God. A fourth major school of thought was Gnostic Christianity, an elaborate theological system characterized by several emanationist cosmologies and the notion of a "divine spark" trapped in matter, which regarded Jesus Christ as a divine being sent by a supreme, Unknown God who pre-existed and was superior to the malevolent Hebrew God of the Old Testament (which was known as Yaldabaoth and conceived as the Demiurge or false creator of the material universe), and who brought salvation through direct, experiential "knowledge" (gnosis).

During the ante-Nicene period, various local and provincial ancient Church councils were held, with the decisions meeting varying degrees of acceptance by different Christian groups. Major Christian figures of the 2nd century who were later declared by the developing proto-Orthodox faction to be heretics were Marcion, Montanus, and Valentinus. In the 4th and 5th centuries AD, after centuries of intermittent persecution, proto-Orthodox Christianity experienced both pressure and recognition from the Roman State and developed a strong episcopal and unifying structure, leading to its legalization under the Emperor Constantine (313 AD).

Beliefs and practices Early Christian communities came to adopt some Jewish practices while rejecting others. Marcion, who believed in the total rejection of Judaism and Jewish scriptures, proposed the rejection of the Old Testament in its entirety and all Jewish practices, but he was excommunicated in Rome and declared to be heretical by the growing proto-Orthodox faction ().

Eschatology

Christianity "emerged as a sect of Judaism in Roman Judea" in the syncretistic Greco-Roman world of the 1st century AD, which was dominated by Roman law and Hellenistic culture. It started with the ministry of Jesus, who proclaimed the coming of the Kingdom of God.Christianity: an introduction by Alister E. McGrath 2006 pp. 16–22 After his death by crucifixion, some of his followers are said to have seen Jesus, and proclaimed him to be alive and resurrected by God. The resurrection of Jesus signified eschatological fulfillment and gave impetus in certain Christian sects to the exaltation of Jesus to the status of divine Son and Lord of God's KingdomLarry Hurtado (December 4, 2018), "When Christians were Jews": Paula Fredriksen on "The First Generation" and the resumption of their missionary activity.

The predominant eschatological view in the ante-Nicene period was premillennialism, the belief of a visible reign of Christ in glory on earth with the risen saints for a thousand years, before the general resurrection and Judgement Day. Justin Martyr and Irenaeus were the most outspoken proponents of premillennialism. Justin Martyr saw himself as continuing in the "Jewish" belief of a temporary messianic kingdom prior to the eternal state.Johannes Quasten, Patrology, Vol. 1 (Westminster, Maryland: Christian Classics, Inc.), 219. (Quasten was a Professor of Ancient Church History and Christian Archaeology at the Catholic University of America) Furthermore according to the Encyclopedia of the Early Church "Justin (Dial. 80) affirms the millenarian idea as that of Christians of complete orthodoxy but he does not hide the fact that many rejected it." M. Simonetti, "Millenarism", 560.Philippe Bobichon, Millénarisme et orthodoxie dans les écrits de Justin Martyr in: Mélanges sur la question millénariste de l'Antiquité à nos jours, M. Dumont (dir.) [Bibliothèque d'étude des mondes chrétiens, 11], Paris, 2018, pp. 61-82 onlineJustin never achieved consistency in his eschatology. He seemed to believe in some sense that the Kingdom of God is currently present. This belief is an aspect of postmillennialism, amillennialism and progressive dispensationalism. In Justin's First Apology he laments the Romans' misunderstanding of the Christians' endtime expectations. The Romans had assumed that when Christians looked for a kingdom, they were looking for a human one. Justin corrects this misunderstanding by saying "For if we looked for a human kingdom, we should also deny our Christ, that we might not be slain and we should strive to escape detection, that we might obtain what we expect." (1 Apol. 11.1-2; cf. also Apol. 52; Dial. 45.4; 113.3-5; 139.5) See Charles Hill's arguments in Regnum Caelorum: Patterns of Millennial Thought in Early Christianity. Additionally however, Philip Schaff, an amillennialist, notes that "In his two apologies, Justin teaches the usual view of the general resurrection and judgment, and makes no mention of the millennium, but does not exclude it." Philip Schaff, History of the Christian Church, Vol. 2 (Peabody, MA: Hendrickson, n.d.) 383. Grand Rapids: Eerdmans, 2001. Irenaeus devoted Book V of his Against Heresies to a defense of the physical resurrection and eternal judgement.Against Heresies 5.32.

Other early premillennialists included Pseudo-Barnabas,"Among the Apostolic Fathers Barnabas is the first and the only one who expressly teaches a pre-millennial reign of Christ on earth. He considers the Mosaic history of the creation a type of six ages of labor for the world, each lasting a thousand years, and of a millennium of rest, since with God 'one day is as a thousand years.' Millennial Sabbath on earth will be followed by an eight and eternal day in a new world, of which the Lord's Day (called by Barnabas 'the eighth day') is the type" (access The Epistle of Barnabas here). Philip Schaff, History of the Christian Church, Vol. 2 (Peabody, MA: Hendrickson, n.d.) 382. Papias, Methodius, Lactantius,Insruct. adv. Gentium Deos, 43, 44. CommodianusAccording to the Encyclopedia of the Early Church "Commodian (mid third c.) takes up the theme of the 7000 years, the last of which is the millennium (Instr. II 35, 8 ff.)." M. Simonetti, "Millenarism", 560. Theophilus, Tertullian,Against Marcion, book 3 chp 25 Melito,Simonetti writes in the Encyclopedia of the Early Church "We know that Melito was also a millenarian" regarding Jerome's reference to him as a chiliast. M. Simonetti, "Millenarism," 560. Hippolytus of Rome, and Victorinus of Pettau.Note this is Victorinus of Pettau not Marcus Piav(v)onius Victorinus the Gaelic EmperorIn his Commentary on Revelation and from the fragment De Fabrica Mundi (Part of a commentary on Genesis). Jerome identifies him as a premillennialist.

Eventually, various Christian eschatological systems developed among different Christian denominations throughout the history of Christianity, providing different frameworks for understanding the timing and nature of apocalyptic predictions. By the 3rd century AD, there was growing opposition to premillennialism. Origen was the first to challenge the doctrine openly."Origen (Princ. II, 2-3)) rejects the literal interpretation of Rev 20-21, gives an allegorical interpretation of it and so takes away the scriptural foundation of Millenarism. In the East: Dionysius of Alexandria had to argue hard against Egyptian communities with millenarian convictions (in Euseb. HE VII, 24-25). M. Simonetti, "Millenarism" in Encyclopedia of the Early Church, Translated by Adrian Walford, Volume 1 (New York: Oxford University Press, 1992), 560. It is doubtless that Origen respected apostolic tradition in interpretation. It was Origen himself who said "Non debemus credere nisi quemadmodum per successionem Ecclesiae Dei tradiderunt nobis" (In Matt., ser. 46, Migne, XIII, 1667). However as it is noted in The Catholic Encyclopedia "Origen has recourse too easily to allegorism to explain purely apparent antilogies or antinomies. He considers that certain narratives or ordinances of the Bible would be unworthy of God if they had to be taken according to the letter, or if they were to be taken solely according to the letter. He justifies the allegorism by the fact that otherwise certain accounts or certain precepts now abrogated would be useless and profitless for the reader: a fact which appears to him contrary to the providence of the Divine inspirer and the dignity of Holy Writ." Dionysius of Alexandria stood against premillennialism when the chiliastic work, The Refutation of the Allegorizers by Nepos, a bishop in Egypt, became popular in Alexandria, as noted in Eusebius's, Ecclesiastical History. Eusebius said of the premillennialian, Papias, that he was "a man of small mental capacity" because he had taken the Apocalypse literally.Eusebius, Historia Ecclesiastica. 3.39.13 According to Dale Allison, in Jewish antiquity less intelligent tanna were deemed more reliable as the intelligent were thought to modify what they were given; Papias's alleged lack of intelligence would not have been a disqualification.

Real presence

Lord's Day

According to Bauckham, the post-apostolic Christian Church contained diverse practices as regards the Sabbath. It seems clear that some of the Early Church considered, in addition to keeping the weekly Sabbath, the importance of also worshipping on the Lord's Day. In the Didache, it states "But every Lord's day gather yourselves together, and break bread, and give thanksgiving."

Infant baptism