How do we get here?

"Dear Pastor,

You should only be opening this letter in the event of my death.

When God calls, there are no regrets.

I've tried to share my heart with you as much as possible, my heart for the nations. I wasn't called to a place. I was called to Him. To obey was my objective. To suffer was expected.

His glory, my reward. His glory, my reward.

The missionary heart cares more than some think is wise, risks more than some think is safe, dreams more than some think is practical, expects more than some think is possible.

I was not called to comfort or to success, but to obedience.

There is no joy outside of knowing Jesus and serving Him.

I love you and my church family.

In His care,

Karen."

Karen was a 20 year old missionary. That's all I know. She lived out the cost of discipleship. How do we get there?