ROME — Responding to confusion about his agreement with the Chinese government, Pope Francis on Wednesday urged Chinese Catholics to trust in his decision to unify the Roman and state-run Catholic churches, assuring his often-persecuted flock that he appreciated their sacrifices but that China represented a “land of great opportunities” for the church.

Under the deal announced on Saturday, a historic breakthrough after 70 years of icy relations between the Vatican and Beijing, the pope recognized the legitimacy of seven bishops appointed by the Chinese government and lifted an order excommunicating them. Through three pontificates, the church had tried to reach an accord with China, but the fate of those seven bishops, and the question of who gets to appoint new bishops in the country, had been impassable barriers.

There were few details about the deal in the Saturday announcement, fueling questions about just how much autonomy Francis had given up to make greater inroads into China, the world’s most populous nation, where the growth of Protestantism is far outpacing the spread of Roman Catholicism. That lack of clarity prompted Francis to write a lengthy letter, released on Wednesday, to the estimated 10 to 12 million Catholics in China.

In the letter, he acknowledged “certain confusion” about the agreement, but did not divulge any new details. Instead, invoking his title as the successor of Peter, he asked Chinese Catholics to “place your trust ever more firmly in the Lord of history and in the church’s discernment of his will.”