The Pope's representative in the United States has singled out the retired televangelist and pastor Robert Schuller for warm praise as a "great evangelical preacher".

The apostolic nuncio, Archbishop Carlo Maria Viganò, told the US bishops' general assembly in Washington how Schuller, by complete dedication to his ministry, "moved countless numbers of people to a real conversion of heart -so many types of people who were willing to sacrifice everything for the sake of Jesus and his Gospel."

A US Catholic diocese recently acquired Schuller's extraordinarily beautiful Crystal Cathedral, the largest glass building in the world which seats more than 2,700 people, and rechristened it Christ Cathedral.

The cathedral was for 34 years the seat of Schuller's ministry, made internationally famous by his Hour of Power programme that went out on Sundays, aimed at Christians and non-Christians.

It was sold after Crystal Cathedral Ministries filed for bankruptcy in October 2010 and is expected to re-open in 2016.

A massive restoration is now under way, described on the Orange diocesan website as a plan to "erase 35 years of wear and tear, and transform it into a breathtakingly unique, beautiful and welcoming Catholic worship space" while respecting its heritage and the legacy and vision of Schuller.

The website describes it as "one of the most challenging architectural, technical, artistic and ecclesiastical undertakings in the history of the Catholic Church." The project is being led by architects and designers Johnson Fain and Ross Clementi Hale Studios, as well as diocesan bishop Kevin Vann.

The reborn Crystal Cathedral will be a physical manifestation of the rapprochement between evangelicals and Catholics that is a cornerstone of the ministry of Pope Francis in Rome.

Archbishop Viganò told the bishops: "We know that the Church, particularly in the United States, has been deeply wounded by the behavior of some priests and bishops by whose deplorable actions the Church's reputation has been strongly shaken. But, we can rebuild the credibility of the Church, through the shining example of so many saints in our very midst, while also being very much aware that within the Church herself, among the people of God, there are both saints and sinners."

Recently, Christian Today reported that Robert A Schuller, son of Robert H Schuller, had said his father was "happy and doing fine" in an assisted living facility in Southern California.

The ministry had gone into decline after the elder Schuller retired in 2006. He is being treated for oesophageal cancer.

Bobby Schuller, Robert H Schuller's grandson, was made new pastor for the Hour of Power last year. Also last summer, the ministry also moved to St Callistus Catholic Church, which occurred in June 2013. Bobby Schuller also pastors at the Tree of Life Community Church in Orange.