The Ministry of the usher goes far beyond opening a door. The purpose of an usher is to present Christ to all that come to worship at church. In a sense, they serve as the host of the building in which believers and strangers gather to seek God. This purpose alone expresses the privilege and responsibility that falls to a church usher.
Ushers are the keepers of the door and the directors of the floor. They see that everything is done decently and in order.