Best-selling American devotional author Philip Yancey says he is "filled with remorse and repentance" after confessing to an eight-year affair with another man's wife.
He is retiring from Christian ministry.
Yancey - author of titles such as What's So Amazing About Grace? and Prayer: Does it Make Any Difference? - wrote in a statement to US-based magazine Christianity Today (CT): "I have failed morally and spiritually, and I grieve over the devastation I have caused.