What is an Ordinance?
A quote by John A. Widtsoe made me think of a statement in the Baltimore Catechism. John A. Widtsoe said this about ordinances, "An ordinance is an earthly symbol of a spiritual reality." The Baltimore Catechism in speaking of sacraments says, "A sacrament is an outward sign instituted by Christ to give grace." I found much in common between these two statements. Today many theologians do not speak so much of sacraments "giving grace" as sacramental celebrations "enabling us to experience grace," to touch Grace itself, to contact the all-pervading presence of the loving God who sustains all created things in existence. This is what I see as the "spiritual reality" in John A. Widtsoe's comment.
An even better source for John A. Widtsoe's statement is from the Presbyterian Westminster Confession of Faith: "A sacrament is an outward sign of an inward grace." I believe the Presbyterians adapted their definition from the Catholics just as John A. Widtsoe adapted his definition from this Protestant source.