Pope Francis said Wednesday that the Holy Spirit unites and grows the Church despite human limitations, sins and scandal.

"The Holy Spirit is the creator of communion, the artist of reconciliation … He builds the community of believers by harmonizing the unity of the body and the multiplicity of its members," Pope Francis said June 19 in St. Peter's Square.

The Holy Spirit "makes the Church grow by helping it to go beyond human limits, sins and any scandal," he said.

Dedicating his Wednesday catechesis to the Acts of the Apostles' account of the descent of the Holy Spirit at Pentecost, Pope Francis reflected on how the Holy Spirit transformed and strengthened St. Peter.

"On the feast of Pentecost, it is Peter who speaks, the rock on which Christ chose to build his Church," he said. "His word, weak and even capable of denying the Lord, when crossed by the fire of the Spirit gains strength and becomes capable of piercing hearts and moving to conversion."

"God in fact chooses what is weak in the world to confound the strong," Pope Francis said, quoting St. Paul's first letter to the Corinthians.

"The Church is thus born of the fire of love -- of a 'fire' that flares up at Pentecost, which manifests the strength of the Word of the Risen One imbued with the Holy Spirit," he said.

Pope Francis explained that this fire symbolically expresses God's work of warming, illuminating, and testing hearts, and His care in purifying and revitalizing human works.

"The Spirit of God moves hearts to welcome the salvation that passes through a person, Jesus Christ, the One whom men nailed to the wood of the cross and whom God raised from the dead," the pope said.

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"As Benedict XVI said, 'This is Pentecost: Jesus, and through Him, God himself, comes to us and draws us into himself," he added.

"Let us ask the Lord to let us experience a new Pentecost, which expands our hearts and tunes our feelings with those of Christ, so that we proudly proclaim His transforming word and bear witness to the power of love that calls to life all that it encounters," Pope Francis said.