St. Paul ends today's first reading with a simple instruction:
Therefore, let us celebrate the feast,
not with the old yeast, the yeast of malice and wickedness,
but with the unleavened bread of sincerity and truth.
Malice and wickedness or sincerity and truth. At first glance it doesn't look like your standard pairs of opposites, but with a closer look we see that's exactly what it is.
The word he uses for malice refers to the interior disposition that is the source of the wickedness, the external act.
The internal disposition we should have is translated here as sincerity, but the word means more. It means clarity in the sense of those streak-free windows in the TV commercials that the sun shines through.
While we don't usually think of truth as the opposite of wickedness. The choice of words makes sense if we understand that by virtue of baptism, "You have become a new creation", and our true self is good. The truth of who we are as adopted children of God manifests itself in good actions. Wickedness is the opposite of our true self.
Paul reminds of a couple of very basic truths.
There is no such thing as accidental sin. Every sin, begins with a malicious thought in the heart, a decision to do wrong.
Second and more importantly if we keep our heart and mind clear what the world will see is the truth, the light of Christ shinning through us.