He was active in the ecumenical movement that sought to find common ground between different Christian denominations.
He also wrote his first book, The Pupil and the Teacher, in 1911, a curriculum intended for Sunday schools most churches operated.
[1][2] Weigle was a member of the ecumenical movement that felt that the doctrinal differences that traditionally divided various Christian denominations were not actually that significant and should not interfere with cross-Christian unity.
He generally considered that the 1st Amendment was intended to disallow government favoritism of any one particular denomination or sect, but that common Christian elements should usually be permissible.
He was opposed to the Supreme Court decisions that restricted school prayer in the United States in 1962 and 1963, and favored a constitutional amendment to allow it more broadly.
The National Council of Churches sought to find a new translation in 20th-century English that maintained the beauty of the KJV, avoided the somewhat stilted language of the ASV, and took into account the various discoveries of ancient manuscripts of Biblical works in the 19th and 20th century.
The work took years, with the final committee meeting and starting its new translation in 1937 at the Yale Divinity School.
Weigle had performed an unusual act among Christian translators of the Bible - he had invited Harry Orlinsky, a practicing Jew, to participate in the translation committee, given Orlinsky's deep knowledge of the Biblical Hebrew language, the Jewish scriptures, and ancient Hebrew literature.
He was later called to testify before Congress in 1960 after an Air Force manual claimed the RSV was created by communist "fellow travelers".
He defended himself against charges of communism, describing himself as a "Republican in politics, a Lutheran in theology, and a Congregationalist in affiliation.