Pope Francis has urged future brothers, nuns and priests to resist commitments they can't fulfil, deriding gossip and fast cars, while praising the use of the humble bicycle.

The Pope was speaking Saturday to more than 6,000 seminarians and men and women from 66 nations considering religious life who were in Rome for four-day pilgrimage as part of The Year of Faith celebrations.

"I think that bicycles are necessary because there's a lot of work to do and you have to move around but get a humbler one." Pope Francis told seminarians and novices July 7 in the Vatican' s Paul VI Hall, Catholic News Agency reports.

The informal audience for about 45 minutes with Pope Francis was held with a papal Mass the following morning.

Pope Francis explained that vocations don't come from catchy campaigns or pursuing personal goals explaining that the consecrated life is the result of prayer and answering an "unsettling" yet loving invitation from God.

The Pontiff said that religious men and women need to shun the temptation of thinking "the latest smartphone, the fastest moped and a car that turns heads" will make them happy.

Materialism and a culture that believes nothing is forever, are some of the greatest dangers inhibiting the way of a happy religious life said Francis.

"And, if you like that beautiful car, think about how many children are dying of hunger, just (think of) that." he told some 6,000 young adults.

"I'm telling you, truly, it hurts me when I see a priest or a sister with a brand new car. But you can't (do that), you can't," the pontiff said.

"Now, you're thinking, 'but then, father, must we go by bike?'" the Pope was asked.

"Bikes are nice," he replied, noting, "Monsignor Alfred goes by bike, he does it."

"Living on the edge" could not provide joy said the pontiff.

"It springs from an encounter, a relation with others, it comes from feeling accepted, understood and loved, and from accepting, understanding and loving others. Don't be afraid of showing the joy of having answered the Lord's call and of giving witness to his Gospel in service to the church."

Pope Franics he was guilty and ashamed of getting embroiled in gossip and complaining urging direct dealing with problems and never talking behind people's backs "to smear them."