It came to mind as I was reading Henri Nouwen's Can You Drink the Cup?, which spells out some of what that poster was getting at (author's emphases included):
"When we are committed to do God's will and not our own we soon discover that much of what we do doesn't need to be done by us. What we are called to do are actions that bring us true joy and peace. Just as leaving friends for the sake of the Gospel will bring us friends, so too will letting go of actions not in accord with our call.
Actions that lead to overwork, exhaustion, and burnout can't praise and glorify God. What God calls us to do we can do and do well. When we listen in silence to God's voice and speak with our friends in trust we will know what we are called to do and we will do it with a grateful heart."