Matthew 24:14, 21

This good news of the kingdom [the gospel] will be preached throughout the whole world as a testimony to all the nations, and then the end [of the age] will come.

For at that time there will be a great tribulation (pressure, distress, oppression), such as has not occurred since the beginning of the world until now, nor ever will [again]. [Dan 12:1; Joel 2:2]