Bestselling author and Christian leader John Stott, 90, has died peacefully in his sleep.

“The evangelical world has lost one of its greatest spokesmen, and I have lost one of my close personal friends and advisors,” said Billy Graham, from his home.

In 2005, Time magazine ranked John Stott among the 100 most influential people in the world.

“His books were popular because they were both theologically sound and easily understood,” noted Michael Foust of the Baptist Press. “Basic Christianity (1958) sold 2 million copies and was translated into more than 60 languages. Other popular titles included I Believe in Preaching (1982), Issues Facing Christians Today (1984), The Cross of Christ (1986) and The Contemporary Christian (1992). He said his goal was to “relate the ancient Word to the modern world.” He wrote more than 40 books.”

He served as chaplain to Queen Elizabeth II for 31 years from 1959 to 1991. Upon his retirement, he was honored with the title “Extra Chaplain.”

One of Stott’s major contributions was at the 1974 International Congress on World Evangelization held at Lausanne, Switzerland, where he was one of the principal authors of the Lausanne Covenant. The Lausanne Covenant provided a theological and historical underpinning for denominations, ministries and individuals committed to sharing the Gospel of Jesus Christ.

Stott was once described as the presumptive “pope” of the evangelicals by Jewish journalist David Brooks of the New York Times. He marveled that the world knew so little about the man who had won exceptional honors and was celibate, humble, articulate and occasionally controversial.

Ordained in the Church of England, Stott served as rector of London’s All Souls Church for more than 20 years.

Stott’s death sparked a round of tributes to him by Christian leaders on their Twitter accounts. Rick Warren, pastor of Saddleback Church in California, called Stott “one of my closest mentors.”

“I flew to the UK recently just to pray for him & sit by his bed. What a giant!” Warren wrote.

Dr. Geoff Tunnicliffe, secretary general of the World Evangelical Alliance, the largest global body of evangelicals, said he was personally impacted by Stott’s teachings. “Uncle John was a great influence in my own theological development. His commitment to biblical orthodoxy, global mission and unity in the body of Christ were foundational in my own spiritual journey,” said Tunnicliffe in a statement.

Stott was the primary author of the Preamble to the 1951 constitution of the WEA, which represents 600 million evangelicals in 128 countries. A major legacy that Stott left is the Langham Partnership International, which trains preachers, funds doctoral education for evangelical thinkers and provides evangelical books to pastors around the world.

“Like Moses,” wrote Chris Wright, Langham’s international director, “he was one of the greatest leaders God has given to his people, and yet at the same time, one of the humblest men on the face of the earth. He was, for all of us who knew him, a walking embodiment of the simple beauty of Jesus, whom he loved above all else.”

“We are saddened by his departure,” wrote Lausanne Movement executive chair S. Douglas Birdsall and international director Lindsay Brown said in a joint statement, “but strengthened with the knowledge that his great confidence and his lifelong hope in Christ has now been made real to him, and his life’s work has been vindicated.”

R. Albert Mohler Jr., president of Southern Baptist Theological Seminary in Louisville, Kentucky, wrote, “You cannot explain English-speaking evangelicalism in the 20th century without crucial reference to the massive influence of John Stott.”

Author and Christian apologist Lee Strobel called Stott a “giant of the faith and a gentle, sweet soul.”