Lessons do not always take the form of lectures in classrooms or wise sages dispensing advice, sometimes we are taught valuable lessons in moments of crisis. Such was true on September 11, 2001 as terrorists sought to break the spirit of America by crashing airplanes into strategic locations on U.S. soil. What was revealed about America was quite telling.

A study of the 9/11 plane highjackers, as shown on the program "60 Minutes II," brought to light the modus operandi used by the terrorists. They would move into new U.S. neighborhoods so as to exploit American isolationism. The idea was that there would be a lack of community in newer neighborhoods and they would thus be left alone. The lesson, as set forth in the televised special, could be reduced to this sobering thought: when Americans become disconnected we become vulnerable to attack.

Edward Hallowell, in his book, "Connect States," writes: “Our society is increasingly obsessed with and enslaved by achieving and increasingly bankrupt and impoverished when it comes to connecting.” 

According to the American Sociological Association, Americans' circle of close confidants has diminished markedly in the last two decades. Americans have many acquaintances but few confidants. 

Robert Putman, author of the book, "Bowling Alone," interviewed over 500,000 people in a 25-year period and came to the conclusion that Americans have become increasingly isolated. He states that Americans are less likely to know their neighbors, to meet with friends or join clubs than a generation ago.

Without meaningful relationships we lose a sense of community. In his book, "Everybody’s Normal Till You Get to Know Them," John Ortberg defines connection as “The sense of being part of something that matters, something larger than ourselves.” -- The Hebrew word, "Shalom" captures this connectedness and literally means, “The webbing together of God.”

After the 9/11 attacks Americans were drawn together in common purpose, patriotism ran high and for a time partisan bickering subsided. Church attendance jumped. 

As time passed partisan bickering increased, patriotism was less visible and church attendance returned to pre-9/11 levels. 

The 9/11 crisis taught us lessons about ourselves, lessons that if unheeded can be more costly than the events of that horrific day. Lest we live in a land of strangers let us return to the values that make our nation great: faith, family and friends.

Rev. Bill Shuler is pastor of Capital Life Church in Arlington, Virginia. To learn more, visit CapitalLife.org.

Fox News Opinion is on Twitter. Follow us @fxnopinion.