Note:  Do not rely on this information. It is very old.

Sabellianism

Sabellianism, a form of heresy in the early Christian Church, held by the followers of Sabellius, who attempted a philosophical definition of the Trinity, and looked on the Son and Holy Ghost, not as distinct persons, but as manifestations of the Godhead. The heresy as such disappeared in the fifth century, but Sabellian views in substance are held by many people at the present day.