Pope Francis, in his first message of the new year on Tuesday, bemoaned a lack of unity across the world, and warned against a soulless hunt for profit that benefits only a few.

"How much dispersion and solitude there is all around us. The world is completely connected, yet seems increasingly disjointed," the pope said in his traditional New Year's Mass in St. Peter's Basilica.

In his homily he paid homage to motherhood, saying a world that looked to the future while forgetting "a mother's gaze" was shortsighted.

"It may well increase its profits, but it will no longer see others as children. It will make money, but not for everyone. We will all dwell in the same house, but not as brothers and sisters," he said.

The New Year's address followed a turbulent 2018 for the pope, whose Church was battered by a torrent of sex scandals across the world that Francis has repeatedly failed to contain.

The sense of crisis was underscored on Monday when the Vatican spokesman and his deputy abruptly and unexpectedly resigned following disagreements on communications strategy.

Pope Francis made no overt reference to the tumult, but called for Roman Catholics to remain rooted to the Church, saying: "Unity counts more than diversity."

He also warned that Church risked becoming "a beautiful museum of the past" if people lost "the amazement of faith."