"A Christian without a church is something purely idealistic, it is not real," the Roman Catholic Church leader argued.
He said that one cannot "understand a Christian alone" any more than "Jesus Christ alone" can be understood.
"Jesus Christ did not fall from the sky like a superhero who comes to save us. No. Jesus Christ has a history. And we can say, and it is true, that God has a history because He wanted to walk with us. And you cannot understand Jesus Christ without His history. So a Christian without history, without a Christian nation, a Christian without the Church is incomprehensible. It is a thing of the laboratory, an artificial thing, a thing that cannot give life," Francis said.
The Vatican leader urged believers to "ask for the grace of memory, the memory of the journey that the people of God has made," as well as for personal memory – "What God did for me, in my life, how has He made me walk."
He added that the "grace of hope" is also necessary for Christian identity, explaining that he does not mean optimism, but "something else."
"Ask for the grace to renew the covenant with the Lord who has called us every day," Francis said.
During Mass on Monday, Francis also theorized about alien life forms, and suggested that even Martians should be welcomed to be baptized as well.
"If – for example – tomorrow an expedition of Martians came, and some of them came to us, here ... Martians, right? Green, with that long nose and big ears, just like children paint them ... And one says, 'But I want to be baptized!' What would happen?" Pope Francis remarked, and told the audience that baptism is open to everyone.
He also recalled the words of Peter: "If then God gave them the same gift He gave to us when we came to believe in the Lord Jesus Christ, who was I to be able to hinder God?"