The Olivet Discourse discusses the signs of the end times and the return of Jesus, emphasizing that the exact day and hour are unknown and only the Father knows. Jesus outlines various signs, including an increase in false prophets, wars, and the abomination of desolation, culminating in a swift return that will catch many unaware. Believers are urged to stay alert and faithful, as the faithful will be rewarded while the unfaithful will face judgment.