The Pope gave his "blessed greeting to the church in Ireland" and to the papal legate, Cardinal Marc Ouellet, head of the Vatican's Congregation for Bishops, who was among the thousands of participants.
Christ's true presence in the Eucharist is a reminder of his gift of self-sacrifice for all humanity, Pope Benedict said. It's also through the Eucharist that Christ becomes nourishment for his flock so as "to assimilate ourselves to him and let us enter into communion with him," which then unites all Christians to one another.
The Pope invited everyone to "join me in praying that the congress will bear rich spiritual fruit in a greater appreciation of our Lord's gift of himself to us in the Eucharist and a deeper love of the mystery of the church, which draws us into ever fuller communion with him and with one another through the daily celebration of the eucharistic sacrifice."
In his catechesis, the Pope continued his series of talks on prayer in the letters of St. Paul, looking specifically at Paul's realization that "God's kingdom comes about not by our own efforts but by the power of God's grace shining through our poor earthen vessels."
In today's world of advanced technology, it's easy to put too much faith in the power and efficiency of human invention, the Pope said.
The power of prayer and God's grace cannot be underestimated, the Pope said, as he called on people to rediscover and give witness to how growing closer to Christ through prayer, reflection and the sacraments changes lives.
What's critical, he said, is a consistent and faithful relationship with God every day, "above all during barren, difficult or painful situations and when God seems absent."
God doesn't banish evil or suffering from people's lives as much as he gives them the strength to withstand and overcome it, he said.
St. Paul learned to face persecution and problems by recognizing his own human weakness and having faith in God's grace, the Pope said.
"We need to have the humility not to rely on ourselves, but to work in the Lord's vineyard, entrusting ourselves as fragile earthen vessels to him."
The more people open themselves up to prayer and contemplation of God's word, the more the Lord will be able to reside in their hearts and "transform our weakness into strength for the Gospel."
"The divine Word, which came to dwell among humanity, wants to live in us, set up his tent within us, in order to enlighten and transform our lives and the world," said the Pope.
Dedicating time to prayer and reflection is not escaping from reality, he said. It is by contemplating and experiencing the peace and beauty of God's love that people face the reality of human weakness and the real presence of evil, and draw the strength needed to help others and make an impact on the world.
At the end of the audience, attended by an estimated 8,000 pilgrims and visitors, the Pope greeted about 110 priests of the Legionaries of Christ, encouraging them as they began a period of pastoral work, "to live this stage of your formative journey as a moment of grace and generous availability."
The Pope also said his prayers were with the world's students who have either begun their summer vacations or are immersed in exams. "May the Lord help you to live this period with serenity, feeling his constant protection," he said.