Eighth. Here the spirit of antichrist, then, is in the first place the spirit of Christ-repudiating Judaism and the Christ-maligning Gentile apostasy. This refers here especially to that of the first century A.D. or anno Domini — ‘after the Lord’ (viz. Jesus) commenced the years of His earthly reign.
The spirit of antichrist does (of course) include also the anti-christ-ian spirit of heathen Rome, as well as the anti-christ-ian spirit of heathen Greek philosophical Gnosticism which opposed the Christian Church. And it also applies to the anti-christ-ian spirit of the modern Papacy, Spiritism, Islam, Communism and Socialism etc.