Vatican City: Corruption can begin with little things and to stay on the right track we need to know how to reject life's temptations - from greed to pride and vanity, Pope Francis said on Friday.

"Many corrupt people, many of the big fish who we read about in the papers, may have started with a small act," Francis said in a sermon as he celebrated mass at the Vatican hotel.

"For example, the tradesman who fiddles the scales so that 900 grams reads as a kilogramme," he said, quoted by Vatican Radio.

"Graft can begin with such small things," he warned, recalling the Devil who in the guise of a serpent tricks Eve into eating the forbidden fruit in the Garden of Eden.

"The Devil is crafty and tries to trick us - he is expert in this."

--IANS