Line 1 has two thoughts that are intended to be parallel: foolish and vain. In line 2, there are also two parallel thoughts: evil and devilish. Line 2 is intended to be a consequence of line 1. The foolish and vain will lead to the evil and devilish.
Lines 3 and 4 set up the essential antithetical parallelism of the next set of lines. Line 3’s “quick to do iniquity” is expanded in lines 6–10. Line 4 is expanded in lines 11–13. As in other cases of literary parallels, I have added the implied parallel phrase in brackets. I strongly suspect that the original language contained the repetition or at least the grammatical implication but that it did not make it through the translation.