Below is an excerpt from Dr. Keller's testimony.
His full testimony can be found by clicking the "about" link above.
Also, you can read more about his vision for Mongolia and how his dental
outreach will play a vital role in that by
second year in China,
while on missionary leave, I was invited to visit the Cofer family. . .
They were just finishing their first mission term in a remote location
in Outer Mongolia. While sharing in their daily ministry, I
was struck by the tremendous health care needs among the impoverished
Hovsgol Province. I also saw how God could use
this deep need for health care clinics to open doors for the spread of
the gospel. At the conclusion of that month-long visit, the Cofers
invited me to join and work alongside them full-time.”