Each Shabbat morning service includes a D'Var Torah (literally a word of Torah, or sermon), delivered by the rabbi. You can find Rabbi Berkenwald's Divrei Torah on his blog: https://rebyehoshua.org/ .
When the congregation comes together to celebrate b'nei mitzvah, the child who is becoming a bar or bat mitzvah also presents a D'var Torah. Here are the texts of these words of wisdom delivered by our youth:
Guest Divrei Torah
Occasionally a D'var Torah is delivered by a congregant or visitor. Here is a collection of guest sermons: