I think President Jimmy Carter is probably the best person to have been President of the United States during my lifetime. There may have been people who accomplished more during their time as President but no one has accomplished more good after their presidency was finished. It has been said that Jimmy Carter was the only President who ever used the White House as a stepping stone to greater things.
He is a great example of humbly working for the things that matter and trying to live out the way of Jesus in trying times.