What does 2 John teach about deceivers and antichrists?

In 2 John, believers are cautioned against deceivers and antichrists who do not confess that Jesus Christ has come in the flesh. This denial undermines the very foundation of the Christian faith, which asserts that Jesus is both fully God and fully man. John emphasizes that those who refuse to acknowledge this truth are not merely mistaken but are actively working against Christ and leading others astray. The presence of such deceivers serves as a reminder for believers to remain vigilant, clinging to sound doctrine as they walk in faith and love.