The Yetsar Hara and the Yetsara Hatoaf

Matzah is the bread of affliction, it's called lechem oni. Another possible interpretation of that name is that it's the bread of humility. So matzah represents being humble and chamez represents being proud. Exodus 12 of 17 has this commandment, you shall guard the matzos. And finally, we've got one more interesting comparison, corruption versus immortality.