I always thought the following verse Matt.24:14 pertained to Christians preaching the gospel to all nations in the world & then shall the end come.

Matthew 24:14, "And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come."  Then the very next verse Matthew 24:15 says, "When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, (whoso readeth, let him understand:)"

In fact this article YouVersion joins Bible translation orgs in global 2033 campaign | Church & Ministries News | The Christian Post states 

"The popular mobile Bible app YouVersion has partnered with an alliance of 10 leading Bible translation organizations to help reach the goal of making the Gospel available to 95% of the world’s population by 2033."

However, the gospel may be preached to all the world a lot sooner than before 2033 because is it not possible that Matt. 24:14 may pertain to the verse in Rev. 14:6, "And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people,"  Then another angel in Rev. 14:9 warns about worshipping the beast and his image and against taking the mark of the beast in the forehead or in the right hand in order to buy and sell."