VATICAN CITY (CNS) -- Resistance to the signs of the Holy Spirit at work is the mark of those with closed hearts who seek to justify their actions with a so-called faithfulness to the law, Pope Francis said.

Instead, Christians are called to be docile, which "ensures that the Spirit can act and go forward in building the church," he said April 14 in his homily during Mass in the Domus Sanctae Marthae.

The day's first reading, from the Acts of the Apostles,recounted Philip who, when prompted by the Holy Spirit, encounters an Ethiopian eunuch reading the scripture. When he asked the eunuch if he understood the passage, "he replied: 'How can I, unless someone instructs me?' So he invited Philip to get in and sit with him."

The pope said the protagonist of the reading was the Holy Spirit while noting that the readings of the past few days focused on the "tragedy" of those who resist the Spirit and whose hearts are "closed, hard and foolish" despite the signs and deeds they have witnessed.

"We saw these things -- the healing of the lame man by Peter and John at the 'Beautiful Gate' of the temple; the words and great deeds done by Stephen -- yet they remained closed to the signs of the Spirit and resisted the Spirit. And they sought to justify this resistance with a so-called faithfulness to the law, that is, to the letter of the law," he said.

However, the day's reading, he said, offers two examples of docility: Philip who, despite his busy work as a bishop, obeyed the Holy Spirit's command to teach and the Ethiopian who experienced joy after opening his heart to the apostle's words.

"Today, we have an example of two men who were docile to the voice of the Spirit. And the sign is joy. Docility to the Spirit is the source of joy," he said.

Pope Francis encouraged the faithful to be open to the Holy Spirit by praying the same prayer taught to Samuel by the high priest Eli: "Speak Lord, for your servant is listening."

"Let us pray like this, many times during the day: when we have doubt, when we don't know or when we simply want to pray. And with this prayer, let us ask for the grace of docility to the Holy Spirit."

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