Verse 7
Which is not another; not another gospel, but only a perversion of the gospel, as is stated in the close of the verse. A similar mode of expression, or rather turn of thought, occurs in 2 Corinthians 11:4.
Galatians 1:8,9. The meaning is simply that it is utterly impossible that there should be another gospel; that is, another system of religious truth, inconsistent with what had been revealed to him.