The B’Nei Yissoschor says that the custom to dress up and wear masks on Purim is a holy Jewish custom. As proof he brings a long piece from the Zohar explaining how Esther putting on the “sovereign garments” (בגדי מלכות) is a reference to Hashem’s concealed Light being clothed within the Sefira of Malchus, that is being clothed in physicality.
Through the mitzvos of Purim our goal is to break all klippos tied with doubt or the idea that we are at all separate from Hashem. Even when the salvation is not as obvious as on Pesach and happens through what appears to be natural means, Hashem is always here with us, clothed within the physical world.
A frailichen Purim! We should all merit to accomplish the yeshuos we need, to perceive Hashem’s constant presence in our lives, and to see the face of Moshiach swiftly in our days!
Yismach Lev 