Pope Francis told nuns and priests to bite their tongues on Monday, during an address marking the end of the Year of Consecrated life.

"If you get an urge to say something against a brother or a sister, to drop a gossip bomb, bite your tongue! Hard!" Francis said to 5,000 members of the clergy.

Central to his address were the themes of prophecy, proximity and hope.

"Prophecy is telling people that there is a path of happiness, of greatness, a path that fills you with joy, which is the path of Jesus," he said. "It is the path of being close to Jesus. It's a gift, it's a charism of prophecy and one must ask the Holy Spirit for it: that I may know how to say the word in the right moment; that I may do that thing at the right moment; that my life, all of it, may be prophetic."

The Pope also reflected on obedience, describing disobedience as "the daughter of the devil". He pointed to the way that Jesus had lived in obedience to the Father; likewise, he said, the obedience of a consecrated person is a "gift of the heart."

On proximity, Francis stressed the importance of different communities engaging with one another and with the world. He said that being a nun or a priest is not a "status" that should separate one from another, but rather it should lead to greater closeness between people of all walks of life.

"To be consecrated doesn't mean ascending one, two, three steps in society. It's true that often we hear parents say: 'You know, Father, I have a daughter who is a religious sister, and a son who is a friar!' And they say it with pride. And it's true! It's a satisfaction for parents to have consecrated children, this is true," he said. "But for [the] consecrated it isn't a state of life that ought to make me look at others like this. Consecrated life must bring me close to people: physical closeness, and spiritual, to know people."

The Pope went on to warn against the "terrorism of gossip".

"Whoever gossips is a terrorist. He or she is a terrorist in the community, because a word against this one, against that one, is as ugly as a bomb... it destroys!" he said. "The one who does this destroys, like a bomb, and he distances himself."

He implored his audience to avoid gossip during the Year of Mercy, saying it would be a "success for the church".

Rather than losing hope in the face of the ageing consecrated community, which "gives us sterility", Francis also called the nuns and priests to pray, as Hannah tirelessly prayed for a son in 1 Samuel, for those truly called to come.

He emphasised the importance of true vocation.

"Some congregations experiment with 'artificial insemination'. What do they do? They welcome... 'Yes come, come, come'. And then there are problems," he said.

"No. We must be serious about who we take. We must clearly distinguish if it is a real vocation, and help it to grow."

The year of Consecrated Life concludes 2 February 2016.