Is Fear Part of Judaism?

Exploring the Rebbe's attitude toward "Yira Tata", a baseline fear of G-d that is usually associated with accepting the yoke of heaven and a fundamental fear of sin. In Chassidus, where our focus is often love and awe of G-d, is there room for this baseline fear? And in the month of Elul, when the King is in the field smiling at us, is Yira Tata still important?