Barack Obama to Americans: Keep changing the world in 2018

As America says goodbye to an undoubtedly turbulent year, former President Barack Obama sent a message of hope and encouraged Americans to "get involved, get engaged and stand up."

Obama took to Twitter Friday morning to point out that - while the year was marked by natural disasters like Hurricane Harvey, violence and racial tension in Charlottesville and the fight against poverty - America's unrelenting spirit of kindness prevailed and ordinary people found ways to make a difference.

He shared the story of a Houston couple who turned their wedding into a volunteer drive benefitting Hurricane Harvey victims, an NFL player who donated an entire season's salary in support of educational equality and a 10-year-old who gave away thousands of "blessing bags" to help Chicago's homeless.

"All across America people chose to get involved, get engaged and stand up. Each of us can make a difference, and all of us ought to try. So go keep changing the world in 2018," Obama added.