This is the PowerPoint outline from the classes I taught at the ACU Lectureship about a year ago. These materials are taken from the book of the same name, also posted on this site. Do We Teach.
This is two lessons, the first dealing with the teachings of Galatians. Galatians teaches that we fall from grace and are alienated from Christ if we teach salvation by the wrong means. I believe that we in the Churches of Christ sometimes run afoul of this teaching, and the consequences are, of course, disastrous.
The second class is on how we fall from grace, which covers much the same grounds as the PowerPoint outline I just posted from the year’s ElderLink.
Galatians specifically warns against man-made requirements in obeying the gospel. In book of Galatians it was requiring the gentiles to live like the Jews (ie circumcision). Requiring someone to do something the Lord has not asked him to do in obeying the gospel is the real danger.