VATICAN CITY — In his homily on Friday, Pope Francis encouraged Christians to remember the first time they felt the love of God and warned that those who forget this moment risk becoming lukewarm and losing salvation.

“Lukewarm Christians: they’re there, immobile. Yes, they’re Christians, but they’ve lost the memory of that first love. And they’ve also lost their enthusiasm,” the Pope told Mass attendees Jan. 30.

“In addition, they’ve lost their patience to tolerate life’s problems with the spirit of Jesus’ love, to tolerate and to bear difficulties on their shoulders. … Lukewarm Christians, poor things, they’re in grave danger,” he said.

Pope Francis centered his reflection on the day’s first reading from the Book of Hebrews, in which St. Paul encourages the people to remember when they were enlightened by the Lord and to keep that memory as a motivation to endure through trials.

Our memory, the Pope noted, “is so important for recalling the grace received, because if we chase away that enthusiasm, which comes from the memory of that first love, then a huge danger arrives for Christians: a lukewarm [faith].”

Those who are lukewarm become “immobile” and lose their ability to deal with life’s difficulties in faith, the Pope continued. He said whenever he thinks about lukewarm Christians, two disturbing images come to his mind.

The first image is when Peter, in his second letter, explains, “The dog turns back to his own vomit, and the sow is washed only to wallow in the mire.”

The second image is when Jesus in the Gospels recounts how a person chases away an evil spirit but lets that spirit back in once it returns with many others. Doing this, the Pope said, is like returning to the vomit of evil that was previously rejected.

A Christian, he observed, has “two parameters: memory and hope. We must evoke our memory so as not to lose the beautiful experience of that first love, which feeds our hope.”

Oftentimes, hope appears in the midst of darkness, but a Christian still goes forward because he has the assurance that “hope never disappoints” and that this hope is found in Jesus, the Holy Father noted.

These two parameters of memory and hope, he said, “are the very frames within which we can safeguard salvation, which comes from the Lord.”

Pope Francis then observed how this salvation must be safeguarded like the tiny mustard seed that grows and bears a large amount of fruit, saying that it’s “painful and heartbreaking” to see so many Christians who only go halfway on the journey to Christ.

“[There are] so many Christians who’ve failed along this road toward a meeting with Jesus. … They’ve lost the memory of that first love and no longer have any hope,” the Pope lamented.

He concluded his homily by praying that all would receive the grace “to safeguard this gift, the gift of salvation.”