Gálatas 5:15

Apparently the believers who advocated grace and the believers who advocated law bitterly opposed one another in the Galatian churches. Paul cautioned both sides to love one another or they would consume each other. That would not be a good example of Christian love. This is the only sin Paul warned the Galatians to avoid. They were better off spiritually than some other congregations to which he wrote, or possibly he did not want to deal with other needs of theirs in this letter.