“the Spirit of truth,
* which the world cannot accept, because it neither sees nor knows it. But you know it, because it remains with you, and will be in you." John 14:17
"But you are not in the flesh; on the contrary, you are in the spirit, if only the Spirit of God dwells in you. Whoever does not have the Spirit of Christ does not belong to him." Romans 8:9
"Do you not know that you are the temple of God, and that the Spirit of God dwells in you?" Corinthians 3:16
The dwelling of God within is based on Scripture and Church teaching;
From the CCC:
738 Thus the Church's mission is not an addition to that of Christ and the Holy Spirit, but is its sacrament: in her whole being and in all her members, the Church is sent to announce, bear witness, make present, and spread the mystery of the communion of the Holy Trinity (the topic of the next article):
"All of us who have received one and the same Spirit, that is, the Holy Spirit, are in a sense blended together with one another and with God. For if Christ, together with the Father's and his own Spirit, comes to
dwell in each of us, though we are many, still the Spirit is one and undivided. He binds together the spirits of each and every one of us, . . . and makes all appear as one in him. For just as the power of Christ's sacred flesh unites those in whom it dwells into one body, I think that in the same way the one and undivided Spirit of God, who dwells in all, leads all into spiritual unity."
"989 We firmly believe, and hence we hope that, just as Christ is truly risen from the dead and lives for ever, so after death the righteous will live for ever with the risen Christ and he will raise them up on the last day. Our resurrection, like his own, will be the work of the Most Holy Trinity:
If the Spirit of him who raised Jesus from the dead
dwells in you, he who raised Christ Jesus from the dead will give life to your mortal bodies also through his Spirit who dwells in you."
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