Pope Francis is not your grandmother's pope. He has been distinguishing his papacy by making gestures of simplicity and humility. 

The new pope's first homily on Thursday was far simpler message than Pope Benedict XVI's first dense homily in 2005. The pastoral-sounding message was another indication of how different a style Pope Francis is approaching his papacy.

In his first public Mass, the new pontiff urged the Catholic Church to preach Jesus Christ in everything it does or risk becoming a just another charity.

In his first homily, the new Argentinian pope urged the Church and its leaders to return to proclaiming the Gospel.

"We can walk all we want, we can build many things, but if we don't proclaim Jesus Christ, something is wrong. We would become a compassionate NGO and not a Church which is the bride of Christ," said Pope Francis, speaking in Latin.

"When we walk without the cross, when we build without the cross and when we proclaim Christ without the cross, we are not disciples of the Lord. We are worldly."

Standing in the Sistine Chapel, the very place where he was elected as the new pontiff, Pope Francis told church leaders that they, too, would not be considered disciples of the Lord unless they confessed Christ.

The same day of his mass, Pope Francis returned to the Church-run residence where he was staying before elected pontiff to insist on paying his hotel bill. He also made his first outing and public debut in a simple white cassock, opting out of the ornate red stole prepared for him.

During his first address, the 76-year-old pope, formerly known as Cardinal Jorge Bergoglio, also bowed before the crowd and the first to take a papal name based on St. Francis of Assisi, taken as a sign of humility. Even in his wardrobe, Pope Francis has kept it simple, wearing the iron cross of his days as a bishop instead of more statement cross traditionally worn by the pope.

After his election, instead of traveling from the Sistine Chapel to the Santa Marta residence in the papal car prepared for him, Francis rode ths bus transporting the other cardinals.

The Vatican spokesman Rev. Federico Lombardi said the difference in style between Francis and Benedict is due to their different background. Pope Francis was a pastor in Buenos Aires while Pope Benedict XVI devoted his life to academics.

Pope Francis will officially inaugurated as pope on Tuesday. The event takes place on the feast of St. Joseph, patron saint of the universal church, said Lombardi.