It has been called the greatest rescue mission of World War II.

Late in that war, American bombers were sent on dangerous missions over southern Europe to cripple the Nazis' oil supplies. Hundreds of crews in flying tin cans soared through storms of anti-aircraft shells. Many American pilots were forced to bail from their shot-up planes. The injured airmen drifted by parachute into occupied Yugoslavia, expecting to be captured or killed.

Instead, on the ground remarkable rescue teams were already in place. Serbian peasants tracked the path of the floating flight crews. Their sole mission was to grab the flyboys and bring them to safety—before the Nazis arrived.

Risking their own lives, the peasants fed and sheltered the downed solders. These rescued men were in friendly hands but on enemy soil. They still needed to escape.

The story of what became known as Operation Haylard builds toward a daring mission, a secret landing strip, and a clandestine evacuation plan. Amazingly, those Serbian peasants rescued every single American airman—over 500 in all.

Here's the fascinating subplot to the rescue. To travel to the evacuation site, the airmen had to spend weeks following the Serbian freedom fighters, who alone knew the path to the evacuation site. Despite the profound language barriers, the direction, the pace, and the destination were in the hands of their rescuers. The men had been saved from their enemy, but the journey had just begun. They still had to walk to freedom.

The story of Operation Halyard sheds light on an important spiritual reality: to be rescued from something sets us on the path toward something.

For the airmen it was a journey of survival. For us it's a journey of faith. The One who saved us is now calling us to walk. It's nonnegotiable. Though snatched from spiritual death, we soon discover that the Christian life isn't an arrival; it's an adventure. Christ rescues us then he points us to the path of following him.

The apostle Paul describes this active view of the Christian life in his letter to the Ephesians, urging them to "walk in a manner worthy of the calling to which you have been called" (4:1).