Modalistic Monarchianism (also known as modalism or Oneness Christology) is a Christian theology that upholds the oneness of God as well as the deity of Jesus Christ. It is a form of Monarchianism and as such stands in contrast with Trinitarianism.

Saint Gregory of Nyssa, Latin Gregorius Nyssenus, (born c. 335, Caesarea, in Cappadocia, Asia Minor [now Kayseri, Turkey]—died c. 394; feast day March 9), philosophical theologian and mystic, leader of the orthodox party in the 4th-century Christian controversies over the doctrine of the Trinity.

The Cappadocians advanced the development of early Christian theology, for example the doctrine of the Trinity, and are highly respected as saints in both Western and Eastern churches.

Sabellius

Montanism was viewed as a heresy of the early church due to its pagan roots which is what church fathers such as Hippolytus deemed heresies to come from – pagan philosophy.

Tritheism (from Greek τριθεΐα, “three divinity”) is a nontrinitarian Christian heresy in which the unity of the Trinity and thus monotheism are denied. It represents more a “possible deviation” than any actual school of thought positing three separate deities.

Trinitarian/Christological heresies

Arianism is often considered to be a form of Unitarian theology in that it stresses God’s unity at the expense of the notion of the Trinity, the doctrine that three distinct persons are united in one Godhead.

The Bible tells us that Jesus died and rose again not only so that we could receive forgiveness, but even more so, He died and rose again so that we might have life. It is through His death and resurrection that we receive life. He died and rose again that we might live for Him – that’s loving service.

In Acts of the Apostles, Jesus appeared to the apostles for forty days, and commanded them to stay in Jerusalem after which Jesus ascended to heaven, followed by the coming of the Holy Spirit at Pentecost, and the missionary task of the early church.