"I know not where..."

I've been thinking a lot about a Martin Luther quote recently:
"I know not where He leads, but well do I know my Guide."

When thinking about where God will lead us in the future, this is extremely encouraging to me for obvious reasons. Along the same line as this, I've also been reading a book called, "The Jesus of Suburbia," and he offers encouragement concerning God's will as well:

"God will guide those whose hearts are open to follow. Its that simple. Be faithful in what God calls you to today, and He will lead you tomorrow...If you have a heart that is passionately trying to do God's will, He will lead you."

See Acts 16:6-10 for Paul's similar situation.