The liturgy must be nurtured with care and never be neglected or abused, Pope Francis said.
"The liturgy is Christ's work and the church's, and as such, it is a living body," he told members of Italy's Association of Professors of Liturgy.
The liturgy "is not a monument made of marble or bronze, it's not a museum piece. The liturgy is alive like a plant, and it must be nurtured with care" and never be "neglected or mistreated," he said.
The pope made his remarks during an audience at the Vatican Sept. 1 with members of the association, which was founded 50 years ago to promote the study and teaching of liturgy at seminaries, departments of theology and other educational institutions.
Pope Francis underlined the importance of progress being rooted in a true sense of tradition.
"Progress in the understanding of, and even in the celebration of, the liturgy must also be rooted in tradition, which always advances in the way the Lord wants," he said. Like with a tree, growth comes from the roots -- from tradition, which is "the assurance of the future."
However, the pope warned there are "many who say, 'According to tradition ...,'" when talking about the liturgy, and "at most they will be traditionalists."
There is a "worldly spirit" of going backward that is "disguised as tradition" and is "fashionable today," he said.
This "backwardism," he said, "is a temptation in the life of the church that leads you to worldly restorationism, disguised as liturgy and theology."
According to the New Testament's Letter to the Hebrews, "We are not among those who draw back," he said. All Christians are called to "go forward, according to the line that tradition gives you. To go backward is to go against the truth and also against the Spirit."
The association, which was founded after the Second Vatican Council to help promote the reception in Italy of the council's teachings on the liturgy, continues to assist the church in this "season" of liturgical reform, the pope said.
This ongoing process "requires time and care, passionate and patient care; it requires spiritual intelligence and pastoral intelligence; it requires formation for a celebratory wisdom that cannot be improvised and must be continually refined," he said.
Their work as experts, researchers and professors requires "synodal" dialogue with others in the fields of theology and the humanities, and with the people of God, who always need the formation and growth that helps their own understanding see "what comes from God and what really leads to him, even in the realm of the liturgy," the pope said.
"We need more than ever today an exalted vision of the liturgy, so that it is not reduced to rambling about rubrical detail" or liturgical rules, he said.
The liturgy must not be "worldly" nor must it turn its back on the world with "worldly exclusivity," he said.
The liturgy must make "people raise their eyes to heaven, to feel that the mystery of Christ dwells in the world and life" and, at the same time, it must be a liturgy for the good of humanity, with its "feet on the ground" and not removed from people's lives, he said.
The liturgy should be "serious (and) close to the people," he said. "The two things together: turning our gaze to the Lord without turning our backs on the world."
The liturgy is not a worldly festivity, nor should it feel "gloomy" or funereal, he said. It is filled with the joy of the Holy Spirit, he said, and it celebrates "the beauty and grandeur of the mystery of God, who gives himself to us."