"One in Christ" is a series of six Bible Studies prepared by Derek Thompson. The title is taken from Galatians 3:28. The studies are aimed at showing that church unity is very much the teaching of Scripture. Also included are two articles by Raymond Williamson to assist group leaders in understanding some of the basic issues in ecumenism. Ray served as General Secretary of the NSW Ecumenical Council from 1986 to 2007 and since retirement has lectured in an Ecumenics Summer School in Australia. Ray's articles are on "Unity in Diversity" and the "Theological Foundations for Ecumenism."

The Bible studies are laid out in such a way that each study can be printed on two A4 pages and handed out to participants. The aim is to open up discussion on relevant ecumenical issues rather than propose solutions to problems. A number of short Bible readings are presented to feed into the discussion. Each study begins and ends in prayer and some suggestions are provided to help those who are not so familiar with praying in groups.

"One in Christ" helps fill the void for ecumenical Bible Studies for groups and is free of charge.