Matthew 24:14: “And this good news of the kingdom will be preached in all the inhabited earth for a witness to all the nations; and then the end will come.”
Matthew 28:19,20: “Go therefore and make disciples of people of all the nations, baptizing them in the name of the Father and of the Son and of the holy spirit, teaching them to observe all the things I have commanded you. And, look! I am with you all the days until the conclusion of the system of things.”
Latter part of revelation talks about judgement will begin at the pulpit. What it means is a preacher,pastor, priest better teach the trueth and not teach "of man" becuase he will be the first one judged.
Matthew 28:19-20 (NIV) Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit,  and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.? This is Jesus speaking after the resurrection before he ascended to Heaven.
Mark 13:10 "And the gospel must first be preached to all the nations." (Mark 13:10) Living Bible. "For nations and Kingdoms will proclaim war against each other, and there will be earthquakes in many lands, and famines. These herald only the early stages of the anguish ahead. But when these things begin to happen, watch out! For you will be in great danger. You will be dragged before the courts, and beaten in the synagogues, and accused before governors and kings of being my followers. This is your opportunity to tell them the Good News . And the Good News must be made known in every nation before the end-time finally comes."( Mark 13: 8-10 ). (Living bible) Somebody else quoted (Matt 24:14) which is a direct command to proclaim this warning message. People can listen or not but they are being warned, about what's coming. And, nobody knows when this is going to happen.