This is metonymy for the Gospel message of Jesus Christ. (See: [[rc://en/ta/man/translate/figs-metonymy]])
## debated with the Grecian Jews ##
Saul sought to reason with the Grecian Jews.
## down to Caeserea ##
there was an elevation change from Jerusalem to Caeserea. However, it is normal to state that one is going up to Jerusalem and up to the Temple, and down when going away from Jerusalem.