ROME – Pope Francis Sunday marked the feast of Pentecost by offering believers a lesson in basic Jesuit spirituality regarding discernment, explaining how the Holy Spirit works and different ways to distinguish the spirit of God from “the spirit of evil.”

Referring to the day’s Gospel reading in which the Holy Spirit descends on the apostles, the pope said that without the Holy Spirit, Jesus’s followers “were alone, by themselves, huddled together.”

“With the Spirit, they were open to all,” he said, adding that “In every age, the Spirit overturns our preconceived notions and opens us to his newness.”

The Holy Spirit, he said, teaches the Church “to be an open house without walls of division.”

Pope Francis spoke during Mass for the solemnity of Pentecost, which commemorates the descent of the Holy Spirit on to the apostles and officially brings the liturgical season of Easter to an end.

He entered the basilica in a wheelchair, which he has been using regularly for the past few weeks due to severe knee pain, which has limited his mobility. As he has often done in recent months, the pope did not celebrate the Mass but rather “assisted” in the ceremony, which was presided over by 88-year-old Italian Cardinal Giovanni Battista Re, Dean of the College of Cardinals.

In his homily, the pope said the role of the Holy Spirit is to give a “new and full understanding” of Jesus’s words and actions.

“God does not want to make us encyclopedias or polymaths,” he said, saying the understanding the Holy Spirit gives is not a question of knowledge, but rather “quality and perspective. The Spirit makes us see everything in a new way, with the eyes of Jesus.”

In terms of where to begin, Francis said the spiritual life starts with love and Jesus’s insistence that “If you love me, you will keep my commandments.”

“We tend to think the exact opposite: if we keep the commandments, we will love Jesus. We tend to think that love comes from our keeping, our fidelity, and our devotion,” he said. “Yet the Spirit reminds us that without love as our basis, all the rest is in vain.”

No matter what problems, worries, or past hurts exist, he said, these are the moments when the Holy Spirit “asks you to let him in. Because he, the Consoler, is the Spirit of healing, of resurrection, who can transform the hurts burning within you.”

Drawing on his Jesuit roots, Pope Francis stressed the importance of being able to distinguish the voice of the Holy Spirit from “the spirit of evil,” saying there are several clues to help in making the distinction.

The Holy Spirit, he said, “will never tell you that on your journey everything is going just fine,” but rather “corrects you; he makes you weep for your sins; he pushes you to change, to fight against your lies and deceptions, even when that calls for hard work, interior struggle and sacrifice.”

On the other hand, the evil spirit, he said, “pushes you to do always what you think and you find pleasing. He makes you think that you have the right to use your freedom any way you want. Then, once you are left feeling empty inside, he blames you and throws you down.”

When feelings of bitterness, pessimism, and negativity arise, “it is good to remember that these things never come from the Holy Spirit,” but are rather from the devil, he said, saying the strategy of evil is to stoke “impatience and self-pity, complaints and criticism, the tendency to blame others for all our problems.”

“It makes us edgy, suspicious, querulous,” whereas the Holy Spirit “urges us never to lose heart and always to start over again,” choosing to spread hope and joy, and “never envying others, but rejoicing in their success.”

Insisting that the Holy Spirit is not “an idealist,” the pope said the spirit urges believers to focus “on the here and now,” whereas the spirit of evil tugs “pull us away from the here and now, and put us somewhere else.”

“Often, he anchors us to the past: to our regrets, our nostalgia, our disappointments. Or else he points us to the future, fueling our fears, illusions, and false hopes,” but the Holy Spirit, he said, “leads us to love, here and now, not an ideal world or an ideal Church, but the real ones, as they are, seen in broad light of day, with transparency and simplicity.”

“How very different from the evil one, who foments gossip and idle chatter,” he said, cautioning against the temptation of the “worldly spirit” to focus on one’s own problems and interests, the need to be relevant, or “our strenuous defense of the nation or group to which we belong.”

The Church cannot be “programmed,” he said, “and every effort at ‘modernization’ is not enough.”

“The Spirit liberates us from obsession with emergencies. He beckons us to walk his paths, ever ancient and ever new, the paths of witness, poverty and mission,” the pope said.