Are All Christians Missionaries?

Look at these two passages and blog below:
Joshua 1:1-9
Matthew 28:18-20
Blog by JD Greear

Questions to ponder after reading:
What do you think about the Spurgeon's statement, the blog, and the passages? 
What feels hard about it? What feels exciting? Was there a recent time where you were keenly aware of being a missionary? What was that like?