Today, the nation celebrates the birthday of American civil rights leader the Rev. Martin Luther King Jr.

One of King's sons, Martin Luther King III, has said that his father's dream of eliminating racism, poverty and violence is still just a dream.

As the years pass, America becomes more vulnerable to complacency about the quest for racial equality.

Too many of us believe that "all men are created equal" is now a reality.

There is plenty of evidence that the struggle needs to press on, even as a unique confluence occurs.

Today also marks the second inauguration of the country's first black president, Barack Obama. Something King didn't get a chance to witness.

It's interesting to take a look at one of King's most challenging quotations: "It is appalling that the most segregated hour of Christian America is 11 o'clock on Sunday morning."

A 2010 study at Baylor University concluded that nine out of 10 congregations in the U.S. continue to have one racial group that accounts for 80 percent or more of the church's members.

The study, as reported by The Associated Press, found several reasons behind the lack of diversity, drawn from a survey of more than 100,000 worshippers from 400 congregations and more than 50 faith groups.

Racial animosity is not a primary cause, the researchers found. Instead, habit and familiarity prompts the under-represented racial group to leave or not join a congregation. "People choose churches where they feel comfortable," Kevin Dougherty, assistant professor of sociology at Baylor, told the Baptist Press in 2010. "Maybe they get challenged there, but they're going for comfort." As a result, other institutions such as schools, the armed services and workplaces, are more diverse.

The quest for equality for all can be uncomfortable. But this week when we honor King's memory we should reflect on our efforts to welcome all races into our lives.