John Sutherland once served as a police superintendent in Great Britain. In a TEDx talk several years ago, he explained a principle in forensic science called Locard’s Exchange principle. The concept was developed by Dr. Edmond Locard, the man known as the Sherlock Holmes of France. His principle has a very simple idea: every contact leaves a trace. Paul Kirk, another forensic expert, put it this way:
“Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks … the paint he scratches … This is evidence that does not forget.”
John Sutherland explained that this principle goes beyond the work of detectives and applies to all our relationships. He said:
“Every time two people come into contact with one another an exchange takes place. Whether between lifelong friends or passing strangers, we encourage, we ignore, we hold out a hand, or we withdraw it. We walk towards or we walk away. We bless or we curse… And every single contact leaves a trace. The way that we treat and regard one another matters. It really matters.”
When Cheryl and I toured Israel with a group of (mostly) Illinois Baptists earlier this year, we made a lot of contacts with the people with whom we traveled. There were many traces left in our lives. We developed new friendships with people we’d never seen before. We renewed old friendships with people we’d known over twenty years ago but had not talked to in a very long time.
The various sites we visited, such as the Sea of Galilee and the city of Jerusalem, definitely impacted our lives. There are “traces” there that will never go away and will affect how we read and hear Scripture. But the traces of friendships renewed and friendships created will probably have just as important an impact on our lives. God has and will continue to use them to teach and transform us.
I say all this as a reminder that every time we make contact with someone in any way, we are leaving a trace that can have a lasting, perhaps eternal, impact. It’s a reason to pray every day that God’s Spirit will fill us and use us to be a blessing to someone else. May we leave traces of Jesus Christ wherever we go.