How is doing a voluntary mitzvah like wearing a snazzy outfit? Parshat Vayikra

Parshat Vayikra opens the third book of Torah by outlining korban, burnt offerings. This week, Rabbi Ari Strulowitz of Midwest NCSY, interprets the wording of the second verse: "a man from among you brings a sacrifice." While some mitzvot are must-do's, many others are voluntary, and so perhaps this sacrifice can be considered a voluntary one. Why does this inform the way we conduct ourselves today?