Reaching the Nations - John

Jesus said in Matthew 28:19-20, “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.”
Our great mandate from Jesus to his church is to go and share the Gospel with all "ethnos", all ethnicities regardless of our where they are.
There are about 3.6 billion who are unreached and 88% are in the area that we call the 10/40 Window. But many are here in America. There are approximately 97 unreached people groups living in the United States.
It is estimated that by 2044, half of the population in America will be a minority. The largest and fastest groups are minorities now, Hispanics are first and then comes the Asian population.
All these groups (and subgroups) by enlarge do not know Jesus.
The question that we as Christians need to consider is why is this happening? Is there something that God is telling us to do? I believe so.