VATICAN CITY, MARCH 26, 2004 ( Given a world that lives as if God did not exist, John Paul II says that the Church must respond with a strong witness of faith, especially through Sunday Mass.

The Pope made that point in his address today to Australian bishops who were ending their five-yearly visit to Rome.

The Holy Father began by observing that "the pernicious ideology of secularism has found fertile ground in Australia."

"At the root of this disturbing development is the attempt to promote a vision of humanity without God," he told the bishops. "It exaggerates individualism, sunders the essential link between freedom and truth, and corrodes the relationships of trust which characterize genuine social living."

Mentioning the reports that each of the pastors of the Australian dioceses had given him on the occasion of the visit, the Pope said that they "unequivocally describe some of the destructive consequences of this eclipse of the sense of God: the undermining of family life; a drift away from the Church; a limited vision of life which fails to awaken in people the sublime call to direct their steps towards a truth which transcends them."

"In the face of such challenges, when the winds are against us, the Lord himself calls out: 'Courage! It is I! Have no fear.' Remaining firm in trust, you too can dispel apprehension and fear," the Holy Father said.

"The Church's witness to the hope that she holds is especially powerful when she gathers together for worship," he continued.

"Sunday Mass, because of its special solemnity, the obligatory presence of the faithful, and its celebration on the day when Christ conquered death, expresses with great emphasis the Eucharist's inherent ecclesial dimension," he said. "The mystery of the Church is made present in a most tangible way."

"Consequently Sunday is the supreme day of faith, an indispensable day, the day of Christian hope," the Pope added.

"Any weakening in the Sunday observance of holy Mass weakens Christian discipleship and dims the light of witness to Christ's presence in our world," he cautioned.

"When Sunday loses its fundamental meaning and becomes subordinate to a secular concept of 'weekend,' dominated by such things as entertainment and sport, people stay locked within a horizon so narrow that they can no longer see the heavens," the Pontiff said.

"Rather than being truly satisfied or revitalized, they remain entrapped in a senseless pursuit of the novel and deprived of the perennial freshness of Christ's 'living water,'" he said.

He continued: "To you as bishops I suggest that, as moderators of the liturgy, you give pastoral priority to catechetical programs which instruct the faithful about the true meaning of Sunday and inspire them to observe it fully."

"Intimately linked to the liturgy is the Church's mission to evangelize," the Pope said. "While the liturgical renewal, ardently desired by the Second Vatican Council, has rightly resulted in a more active and conscious participation of the faithful in the tasks proper to them, such involvement must not become an end in itself. The purpose of being with Jesus is to go forth from Jesus, in his power and with his grace."

"It is precisely this dynamic that the prayer after Communion and the concluding rite of the Mass articulate," he said, echoing a theme from his 1998 apostolic letter "Dies Domini" (The Lord's Day).

"Sent by the Lord himself into the vineyard -- the home, the workplace, schools, civic organizations -- disciples of Christ find no room for 'standing idle in the marketplace' nor can they be so deeply immersed in the internal organization of parish life, that they are distracted from the command to evangelize others actively," the Holy Father said.

He added: "Renewed by the strength of the risen Lord and his Spirit, Christ's followers must return to their vineyard burning with a desire to speak of Christ and to show him to the world."