VATICAN, July 29, 2010 (CNS) -- The head of the Vatican's missionary office urged bishops and priests in China to live simply, show kindness to all people and continue working for the unity of the Catholic community on the mainland.

Cardinal Ivan Dias, prefect of the Congregation for the Evangelization of Peoples, wrote to Chinese bishops and priests July 5; the text of his letter was released July 29 by Fides, the congregation's news agency.

Reflecting on the themes Pope Benedict XVI highlighted during the Year for Priests, which ended in June, Cardinal Dias said bishops and priests must remember they are ministers of Christ and his forgiveness, servants of all people and promoters of the unity of the church.

Promoting unity, he said, requires both communion with the pope and with other Catholics.

"We are all too aware of how some of you suffered in the recent past because of loyalty to the Holy See," he said. "The exemplary and courageous loyalty toward the See of Peter demonstrated by Catholics in China is a precious gift of the Lord."

When China began suppressing the church in the late 1950s, it established the Chinese Catholic Patriotic Association, whose members initially were asked to reject ties with the Vatican.

Catholics who refused to join the patriotic association and overtly maintained their loyalty to the Vatican suffered decades of persecution.

Being Catholic and obeying the will of Christ that his followers be one means Catholics must be in union with one another, Cardinal Dias said.

"This important challenge you are already tackling," he said, as bishops and priests try to promote reconciliation between those who practiced their faith clandestinely and those who participated in officially sanctioned activities with the patriotic association.

Cardinal Dias reminded the bishops and priests of what Pope Benedict said in his homily for the June 29 feast of Sts. Peter and Paul about attacks on the church and persecution of Christians having a long history, yet never being able to defeat the church completely.

On the other hand, the cardinal said, the pope noted how the church "is subjected to the greatest danger by what pollutes the faith and Christian life of her members and communities."

The pope said that "one of the typical effects of the action of the Evil One is, precisely, the internal division of the ecclesial community," the cardinal wrote.

Cardinal Dias also urged each Chinese bishop and priest to be a man of prayer and simplicity and to show special concern for the poor and needy, including "sheep who do not yet belong to his fold."