The liturgy is an exercise of the priestly office of Jesus Christ. In the liturgy the sanctification of humankind is signified by signs perceptible to the senses, and is effected in a way which corresponds with each of these signs.

The sacraments of the Church are usually defined as ‘signs instituted by Christ that confer the grace that they signify’. Thus, the sacraments are the most intense instances of the Church’s liturgical life.