Modalism (i.e. Sabellianism, Noetianism and Patripassianism)
...taught that the three persons of the Trinity as different “modes” of the Godhead. A typical modalist approach is to regard God as the Father in creation, the Son in redemption, and the Spirit in sanctification. In other words, God exists as Father, Son and Spirit in different eras, but never as triune. Stemming from Modalism, Patripassianism believed that the Father suffered as the Son.
Arianism
...taught that the preexistent Christ was the first and greatest of God’s creatures but denied his fully divine status. The Arian controversy was of major importance in the development of Christology during the fourth century and was addressed definitely in the Nicene Creed.
Docetism
...taught that Jesus Christ as a purely divine being who only had the “appearance” of being human. Regarding his suffering, some versions taught that Jesus’ divinity abandoned or left him upon the cross while other claimed that he only appeared to suffer (much like he only appeared to be human).
Ebionitism
...taught that while Jesus was endowed with particular charismatic gifts which distinguished him from other humans but nonetheless regarded Him as a purely human figure.
Macedonianism
...that that the Holy Spirit is a created being.
Adoptionism
...taught that Jesus was born totally human and only later was “adopted” – either at his baptism or at his resurrection – by God in a special (i.e. divine) way.