We turn once again to the nature of the liturgy in the Constitution on the Sacred Liturgy.
The word liturgy literally means ” public work”. As Article 9 notes, though, “The sacred liturgy does not exhaust the entire activity of the Church.” People must first be called to conversion. We need evangelization.
Article 10 follows with one of the most quoted and profound passages from the document: “Nevertheless the liturgy is the summit toward which the activity of the Church is directed; at the same time it is the font from which all her power flows.”
Here are the Scripture references:
And the footnotes:
 Cf. Matt. 28:20.
 Postcommunion for both Masses of Easter Sunday.
 Collect of the Mass for Tuesday of Easter Week.