The Greek ke·rysʹso, which is commonly rendered “preach,” means, basically, ‘make proclamation as a herald, to be a herald, officiate as herald, proclaim (as conqueror).’

Ke·rysʹso thus does not convey the thought of the delivery of a sermon to a closed group of disciples but, rather, of an open, public proclamation. This is illustrated by its use to describe the “strong angel proclaiming [ke·rysʹson·ta] with a loud voice: ‘Who is worthy to open the scroll and loose its seals?’”​—Re 5:2; compare also Mt 10:27.