Pope Francis thanked those who are dedicated to promoting life and defending conscientious objection.
And he also prayed that the Catholic Church in China may live in greater communion with the universal church in freedom and tranquility.
The pope's remarks came May 22 after he led the recitation of the "Regina Coeli" prayer with visitors in St. Peter's Square.
Greeting those in the square who had taken part in Italy's national "Let's Choose Life" march in Rome the previous day, Pope Francis said, "I thank you for your dedication in promoting life and defending conscientious objection, which there are often attempts to limit."
He said there has been a change in mentality over the years that has led to people believing "that life is a good at our complete disposal, that we can choose to manipulate, to give birth or take life as we please, as if it were the exclusive consequence of individual choice."
"Let us remember that life is a gift from God," he said. "It is always sacred and inviolable, and we cannot silence the voice of conscience."
The pope also asked people to pray for Catholics in China in the run-up to the feast of Our Lady, Help of Christians May 24.
He said he wanted to assure Catholics in China "once again of my spiritual closeness. I am attentively and actively following the often complex life and situations of the faithful and pastors, and I pray every day for them."
Ten days before the pope offered his prayer, Hong Kong's national security police detained 90-year-old Cardinal Joseph Zen Ze-kiun, the retired bishop of Hong Kong, and three other trustees of a fund that had been set up to provide financial assistance to people involved in anti-government protests in 2019. The fund has since been disbanded.
The pope asked people to pray "so that the church in China, in freedom and tranquility, might live in effective communion with the universal church, and might exercise its mission of proclaiming the Gospel to everyone, and thus offer a positive contribution to the spiritual and material progress of society as well."
In his main address, the pope reflected on the Sunday Gospel reading from St. John in which Jesus tells his disciples during the Last Supper, "Peace I leave with you; my peace I give to you."
The pope said it is the Holy Spirit, "who disarms the heart and fills it with serenity" and who "loosens rigidity and extinguishes the temptations to attack others."
The Holy Spirit reminds people that those in our midst are brothers and sisters, "not obstacles or adversaries" and he "gives us the strength to forgive, to begin again" and become men and women of peace, he said.
"The more we feel our hearts are agitated, the more we sense we are nervous, impatient, angry inside, the more we need to ask the Lord for the Spirit of peace," he said.
Pray each day for the gift of peace, the pope urged, "and let us also ask this for those who live next to us, for those we meet each day, and for the leaders of nations."