Question: Why do we eat the Maror (Bitter Herbs) on Passover?
Answer: God commanded us to eat 3 foods on the first night of Passover to remember 3 aspects of the miraculous way we were freed from Egyptian slavery. The Matzah reminds us of the instantaneous way hundreds of thousands of slaves were freed. The roasted lamb (which we do not eat nowadays since the lamb must be slaughtered on the Temple Mount in Jerusalem) reminds us that our freedom was in order to serve God, and the Marror reminds us of the bitter days of slavery.
All the Best,
Rabbi Azriel Schreiber