Who can do a blessing? The Catechism states, "Every baptized person is called to be a 'blessing' and to bless. Hence lay people may preside at certain blessings; the more a blessing concerns ecclesial and sacramental life, the more its administration is reserved to the ordained ministry (bishops, priest, deacons)" (No. 1669).
Priests are the ordinary ministers of blessings, asking God's help for those people being blessed or dedicating something to a sacred service; the priest's blessing is imparted with the weight of the Church and therefore has great value in the eyes of God. The blessing of a layperson upon another, such as a parent blessing a child, is an act of good will whereby the person implores God's aid for the person; the value of this blessing in the eyes of God depends upon the person's individual sincerity and sanctity.
Blessings are categorized into two types: invocative and constitutive.
In an invocative blessing, the minister implores the divine favor of God to grant some spiritual or temporal good without any change of condition, such as when a parent blessed a child. This blessing is also a recognition of God's goodness in bestowing this "blessing" upon us, such as when we offer a blessing for our food at meal time. In blessing objects or places, a view is also taken toward those who will use the objects or visit the places.
A constitutive blessing, invoked by a bishop, priest or deacon, signifies the permanent sanctification and dedication of a person or thing for some sacred purpose. Here the person or object takes on a sacred character and would not be returned to non-sacred or profane use. For example, when religious Sisters or Brothers profess final vows, they are blessed, indicating a permanent change in their lives. Or, when a chalice is blessed, it becomes a sacred vessel dedicated solely to sacred usage.
