Parabasis is often translated "transgression". Hamartia is "sin". But what is the difference between them and what difference does it make to our understanding of biblical texts that use these terms?
Parabasis means a transgression of a known law i.e. is more deliberate.
Hamartia is sin in a more general sense, including sin even where there is no knowledge of the law.
But, again, does that change our understanding of passages that use these words, especially passages that use both and imply a distinction?