These two phrases mean basically the same thing and emphasize that God will avenge his people. AT: "I will certainly avenge you" (See: [[rc://en/ta/man/translate/figs-parallelism]])
Paul speaks of the blessings that the enemies will receive as if someone were pouring hot coals on their heads. Possible meanings are 1) "make the person who harmed you feel badly about how he has mistreated you" or 2) "give God a reason to judge your enemy more harshly." (See: [[rc://en/ta/man/translate/figs-metaphor]])
Paul describes "evil" as though it were a person. You can translate this in an active form. AT: "Do not let those who are evil defeat you, but defeat those who are evil by doing what is good" (See: [[rc://en/ta/man/translate/figs-personification]] and [[rc://en/ta/man/translate/figs-activepassive]])