If Catholics do not proclaim Jesus with their lives, then the Church becomes "not the mother, but the babysitter," Pope Francis cautioned in a homily and a separate letter to his brother bishops in Argentina.

When believers share their faith, "the Church becomes a mother church that produces children (and more) children, because we, the children of the Church, we carry that. But when we do not, the Church is not the mother, but the babysitter, that takes care of the baby – to put the baby to sleep. It is a Church dormant," Pope Francis stated.

The solution to this is "to proclaim Christ, to carry the Church – this fruitful motherhood of the Church – forward," he said.

The Pope first mentioned the importance of being spiritually fruitful during the April 16 Mass he celebrated for employees of the Vatican's Institute for Works of Religion in St. Martha's residence.

He based his homily on a reading from the Acts of the Apostles, which recalled the lives of the first Christians.

"They left their homes," he recalled, "they brought with them only few belongings, and going from place to place proclaiming the Word.

"They were a simple faithful, baptized just a year or so – but they had the courage to go and proclaim," the Pope said.

Pope Francis then turned to a point that he emphasized frequently in Buenos Aires.  

The early Christians, he stressed, had nothing but "the power of baptism," which "gave them apostolic courage, the strength of the Spirit."

But, he asked, do Christians today really believe in the power of their baptism?

"Is it sufficient for evangelization? Or do we rather 'hope' that the priest should speak, that the bishop might speak?"

This way of seeing Christianity often carries with it the attitude of, 'I was baptized, I made Confirmation, First Communion ... I have my identity card, alright.' And now, go to sleep quietly, you are a Christian," the Pope explained.

Instead, he said that believers must be "faithful to the Spirit, to proclaim Jesus with our lives, through our witness and our words." Pope Francis repeated this message in a letter he sent to his fellow Argentinian bishops who are meeting for their annual full assembly in Pilar, Argentina.

"Mission," he underlined, "is key to ministry."

"A Church that does not go out of itself, sooner or later, sickens from the stale air of closed rooms," the Pope wrote.

He acknowledged that in going out the Church runs risks, but "I prefer a thousand times over a Church of accidents than a sick Church."

The Church, the Holy Father observed, typically suffers from being self-referential, only looking to and relying on itself.

This kind of self-centeredness "leads to a routine spirituality and convoluted clericalism" and prevents people from experiencing the sweet and comforting joy of evangelization, he warned.

Pope Francis finished his letter by greeting the Argentinian people and asking his fellow bishops to pray "I do not grow proud and always know how to listen to what God wants and not what I want."