This may be new for some but in the New Testament the "world" mentioned in the scriptures is not the entire planet as we know it today. The "world" was the Roman Empire (Luke 2:1; Acts 2:5; Acts 17:6; 1 Tim. 3:16).

In fact, Paul said the gospel had been preached throughout the whole "world" (Romans 1:8, Romans 10:18, Romans 16:26, Colossians 1:6, Colossians 1:23, Titus 2:11).

Now that we know this, What was the end that took place in Matthew 24:34?

Side Note:

The word "world" in Matthew 24:14 is the Greek word "oikoumene" (ecumene) in this case, it means "the habitable world, Under the Roman Empire". In the first century they saw their world as the inhabited earth. We know this is true because Jesus tells us in Matthew 24:34 "this generation will not pass away until all these things take place" When Jesus uses "this generation" it means the generation to whom He is speaking to. This is why we know "oikoumene" refers to the first century Roman Empire it's in the time frame of "this generation."

Now, check this out, Matthew uses oikoumene only in Matthew 24:14 nowhere else. He later uses kosmos for "world" nine times later in his epistle. But do you know why he used oikoumene only in 24:14? He wants the reader to know its local geographical fulfillment within the time frame of "this generation". Matthew wants the reader to know the difference and later he uses kosmos instead.