καὶ ὑμεῖς δὲ μαρτυρεῖτε, ὅτι ἀπ᾽ ἀρχῆς μετ᾽ ἐμοῦ ἐστε.

1. καὶ
   and
2. ὑμεῖς
   you
3. δὲ
   but
   and
4. μαρτυρεῖτε
   you testify
   bear witness, testify
5.  
   ,
    
6. ὅτι
   that
   because
7. ἀπ᾽
   from
8. ἀρχῆς
   beginning
9. μετ᾽
   with
10. ἐμοῦ
    me
11. ἐστε
    you are
    are
12.  
    .
     

And you also testify, because you are with me from the beginning.