Concerning the end of the world and when this will happen Mark 13:10 says:
And the gospel must first be preached to all nations. (NIV)
Has the gospel been preached to all nations?
The word translated 'nations' is ἔθνος (ethnos), from which we derive the word 'ethnic'. It is talking about ethnic communities, which we might call people groups today, not political states.
The Joshua Project estimates that there are 16,825 people groups in the word. Of those, 7,287 are unreached, by which they mean "less than 2% Evangelical Christian and less than 5% Christian Adherents". Because there are so few Christians in an unreached people group they will struggle to evangelise their own group with the gospel, which means many Christians believe they need outside missionary help. This represents 2.91 billion people.
The International Mission Board estimates there are 2,945 unengaged people groups. An unengaged people group is one where there are no Christian in the group, and no plan for anyone to take the gospel to them. They estimate there are over 190 million people in unengaged people groups.
I believe this was fulfilled. In Col. 1:23, the apostle Paul wrote,
At least, if you choose to believe it was fulfilled, you have a biblical justification for doing so.
This isn't opinion based, and is a question which can be answered according to biblical standard.
There might be about 41,000 Christian denominations, many of which preach different versions of Christ. So that would mean there are 41,000 different Christ's. We know this, because Christ promised to be one flock, one shepherd (John 10:16).
So there are 41,000+ competing Christs, many of which do not actively preach.
There are a few versions of Jesus taking the lead in preaching, but have to relearn his own gospel from the ground up -- making a rather finicky stance in the final word on life or death relative to this age -- the all-important gospel which is completed before the end.
So some of the older versions of Jesus have the most sin attributed to their name (Child molestation, etc) in effect mocking his name. Some of the newer ones are learning from the ground up, having splintered from the older Jesus due to stumbling.
A divided Christ in a divided world - hard to judge if the true gospel is being preached at all.
Matthew 12:26 states it perfectly.
HOWEVER IN CONTRAST: If you consider the bible itself (the word) as the authority and consider corrupt people as an irrelevancy, and give the bible it's credit to take root in hearts despite its imperfect transmitters if the word, THEN we can certainly say progress has been made on an extraordinary level.
Before even trying to unravel the mystery behind Jesus statement in Mark 13:10 we need to first determine just what and who Jesus meant. The two key words here are published and nations.
King James translation
Definitions of the Greek words:
Since Jesus spoke Aramaic and the Gospels were written in Greek we can not know for certainty these are accurate meanings, but since Greek is a verb oriented language, the meanings must be very near exact.
So We can say with assurance that what Jesus was saying is that the Gospel must be proclaimed to all tribes, which also would be all languages.
So how many languages are there?
Much pioneering work in documenting the languages of the world has been done by missionary organizations (such as the Summer Institute of Linguistics, now known as SIL International) with an interest in translating the Christian Bible. As of 2009, at least a portion of the bible had been translated into 2,508 different languages, still a long way short of full coverage.
I may be wrong, but as I see it that Scripture will be fulfilled when the Bible is translated into all those languages and presented to them.
Much translation has been done since 2009, but I am unsure how many are left to be translated and published.
Colossians 1:6 (GOD'S WORD® Translation)
Colossians 1:23 (New Living Translation)