The corruption of early Christian monotheism emerged during the apostolic age, as warned by Paul and Peter against false teachings infiltrating assemblies. Paul and Jude emphasized the necessity for believers to defend their faith against heresies propagated by figures such as the Nicolaitans and Cerinthus. John, residing in Ephesus, bolstered apostolic teachings through his writings, asserting the unity of Jesus as both Christ and man, countering contemporary heresies and reaffirming Christ's preexistence and incarnation.
Living as a Christian in this World 