The Major Early Christian Heresies
Heresies that Began in the Apostolic Era
Judaism* - that the Jewish law is still fully in force as a requirement for salvation
Preterism - that the final judgement and resurrection of the dead has already happened
Docetism - that Jesus did not come in the flesh
Gnosticism - that the material word is inherently bad, extreme asceticism, access to secret knowledge not publicly proclaimed by the apostles and reserved only for the elite, intermediary deities between God and material creation
* This is obviously a controversial title for the heresy of the Judaizers but I think it is accurate.
Heresies that Began in the Ante-Nicene Era (2nd/3rd Centuries)
Adoptionism - that Jesus was born of sexual union between Mary and Joseph and was adopted as the Son of God upon his baptism (or some other occasion), not declared a heresy in a preserved written record until the post-apostolic era
Separatism - that the Christ existed separately from the man (at least at some point during the earthly life of Jesus)
Marcionism - that the OT God was not all-good and is different from the NT God, rejection of the Jewish scriptures, and only accepted Paul as an apostle
Montanism - that the utterances of prophets are on par with scripture, had a number of practical differences with the proto-orthodox, but was not strictly a heresy
Manicheanism - an eclectic blend from different religions, gnostic dualism
Patripassianism - that God the Father suffered during Jesus' passion
Sabellianism - that the Father, Son, and Holy Spirit are one person that have different roles at various times
Monarchianism - that God is absolutely one to the extent that there cannot be a different Son that is also God, the most popular form states that Jesus is only a man
The most pervasive heretical groups in the Ante-Nicene church were the Marcionites, Manicheans, Montanists, Ebionites/Nazarenes, and Adoptionists. They had their own churches for many centuries. In some places they were the dominant forms of Christianity until they were wiped out by the Arab invasions and persecutions under the Catholic Roman Empire. Gnosticism was widespread as a spiritual movement but, while some groups such as the Valentinians held unauthorized gatherings, most gnostics existed wiithin the structures of the proto-orthodox church.
Heresies that Began in the Nicene and Post-Nicene Eras
Arianism - that the Son was created and is not the same substance as God
Pneumatomachianism - that the Holy Spirit is not God, means "spirit fighters"
Nestorianism -that the human nature and divine nature of Jesus Christ form one compounded person (in the "orthodox" position there is no human person but only human nature) that has two different functions that cannot be attributed to each other, ex. Mary cannot be called the "Mother of God"
Apollinarianism - that Christ had an incomplete human nature
Monophysitism - that the humanity and divinity form one nature in Christ
Monothelitism - that there is only one will in the person of Christ, tended to minimize its human side
Donatism - that the Church is made up only of saints, the lapsed cannot be reinstated, not technically a heresy but a schism
Arians, Nestorians, Monophysites, and Donatists had ecclesiastical structures that lasted for centuries, especially outside of the Roman Empire. Nestorians continue to exist as the Church of the East. Monophysites, more ecumenically referred to as non-Chalcedonians, continue to exist as the Oriental Orthodox Church which consists of five autonomous churches: Coptic, Syrian, Armenian, Indian, and Ethiopian churches.