if I do not go away, the Comforter will not come to you

You can translate this in a positive form. AT: "the Comforter will come to you only if I go away" (See: rc://en/ta/man/translate/figs-doublenegatives)

Comforter

This is a title for the Holy Spirit who will be with the disciples after Jesus goes away. See how you translated this in John 14:26.