We send the messengers only to Proclaim good news and to give warnings but with false arguments the unbelievers seek to defeat the Truth, through mocking at My revelations and My warnings.
Meaning:-
Proclaim: to announce or declare
false: incorrect, not true or accurate, wrong.
mocking: to attack or treat with ridicule, contempt, or derision, to ridicule by mimicry of action or speech; mimic derisively.
Revelations: revealed by God to humans, the Book of Revelations.