Well, in verse 2, 'Every spirit that confesses that Jesus Christ has come', that is a perfect participle in Greek. 'Is come' is in the old English sense of 'has come'. 'The master is come and calls for you.' That is old English for 'has come'. Modern French is similar, Je suis venu, 'I am come', meaning 'I have come'.
You shouldn't trust me, you know—apprentice that I am in Greek! But as far as I know, this is a perfect participle. You could argue it means 'has come' and the effect of that coming remains, but normally you wouldn't use that perfect participle of a future event.
