Passage
and ye too bear witness, because ye are with me from [the] beginning.
and ye too bear witness, because ye are with me from [the] beginning.
John 15:25 But that the word written in their law might be fulfilled, They hated me without a cause.
John 15:26 But when the Comforter is come, whom I will send to you from the Father, the Spirit of truth who goes forth from with the Father, *he* shall bear witness concerning me;
John 15:27 and ye too bear witness, because ye are with me from [the] beginning.
The verse centers on "bear", "witness", and "beginning". It is saying that the verse draws attention to "bear" and "witness", so its meaning should be read from those terms before moving to application.
The prior verse says "But when the Comforter is come whom...", giving immediate footing for "bear" and "witness". In John context, the local focus is the identity of Jesus, new birth, eternal life, and belief and unbelief.
A plain takeaway is to answer the verse's own emphasis on "bear" and "witness" with trust shaped by these words, not by a vague optimism outside the passage.