One of the Gospel readings for Pentecost details our Lord’s promise to send the Holy Spirit to His disciples. In an earlier related chapter from John’s gospel, Christ Himself walks with the disciples and predicts His own Passion. He assures the disciples that they will not be abandoned as orphans, but will share in the very life of the Most Holy Trinity (John 14:15-31)! The consolation and comfort Jesus brought to those gathered in the Upper Room after His death and resurrection surely reminded them of this though He ordered them to not leave Jerusalem until “the promise of the Father” had been sent (John 20:19-23). It would not be until after Christ’s ascension, that the Holy Spirit would be sent upon the disciples and so enable them to carry out the Great Commission of our Lord, “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything that I have commanded you.” While Christ had sent out the disciples to evangelize before (see Luke 10:1-20, cf. Matthew 10), these efforts were limited to “the lost sheep of the house of Israel.” Proselytizing the rest of the world would take place after the rejection of our Lord and would require grace to sustain the disciples through this incredible evangelical endeavor.
Today, the faithful are not only entrusted with this mission, but have also been baptized and confirmed with the same Holy Spirit as was promised to Christ’s first followers! The Holy Spirit is truly God and is inseparable from the Father and the Son. Though Christ is seen, it is the Spirit who reveals Him. Thus, both are on a “joint mission” to reveal the visible image of the invisible God (see CCC 689). The Holy Spirit invites us to better know the Father and Son. Each person of the Trinity more fully deepens our understanding of God. As the Catechism says: