Understanding God's commandments and church doctrine is useless if those truths aren't put into practice, Pope Francis said.
"A faith without bearing fruit in life, a faith that doesn't bear fruit in works is not faith," the pope said in a Mass homily, focusing on the day's first reading from the Book of James (2:14-24).
Professing the faith without giving a witness makes the Gospel "words and nothing more than words," he said Friday during his early morning Mass in the Domus Sanctae Marthae, where he lives.
"We, too, make this mistake many times," he said. It's often the case when a person thinks, "'But I have lots of faith. I believe everything.'"
However, look at how that person lives life. It may be "a lukewarm, weak life" where "faith is like a theory" and not lived out in practice, the pope said.
"You may know all the commandments, all the prophesies, all the truths of the faith, but if this isn't put into practice, is not translated into works, it serves nothing." As the Apostle James noted, even demons know the Creed, but that doesn't mean they have faith, the pope said.
Christians can be this way, too, he said, seeing the faith "as a system of ideas." But in reality, such people are what James considered them to be, "the anti-Christ, ideologues of the faith," the pope said.
"Having faith isn't having knowledge," the pope said. Instead, it is "receiving God's message" as brought by Christ.
There can be people who know very little or nothing about doctrine, "but have lots of faith" because rather than embracing "abstract truths," they embrace the living Christ, the pope said.
"Faith and witness are indissoluble," he said. "Faith is an encounter with Jesus Christ, with God," and always leads to witnessing.
"A faith without works, a faith that doesn't get you involved, isn't faith," he said. "It's words and nothing more than words."