The man scheduled to give the invocation at Barack Obama’s inauguration tomorrow gave a keynote address at the Ebenezer Baptist Church in Atlanta. That’s the church where Dr. Martin Luther King, Junior preached decades ago.

Pastor Rick Warren urged the crowd to follow King’s example of service and selflessness. He also told the audience the feats of Dr. King and Mr. Obama are giant steps in the right direction, saying “Martin Luther King was a mighty tool in the hand of God. But God isn’t through. Justice is a journey and we’re getting further and further along.”

Meanwhile in DC, Obama led the nation in a Day of Service. He started the day visiting patients from Iraq and Afghanistan at Walter Reed Army Medical Center. He then joined Martin Luther King III at an emergency shelter for homeless teens.

While there, Obama imparted a few words from Dr. King: “If you sweep floors for a living, make sure you’re the best floor sweeper there is.”

Obama also stopped off at a DC high school where hundreds of volunteers were busy sending letters to troops and decorating blankets for soldiers. He talked to them about continuing their service throughout the year.

Later tonight, he heads to an Inauguration Dinner were John McCain will be the guest of honor.

King would have been 80 years old on Thursday.