John 7:39 (But this spake he of the Spirit, which they that believe on him should receive, for the Holy Ghost was not yet given: because that Jesus was not yet glorified.)
John parenthetically explains the saying of Jesus that rivers of living water shall flow out of the belly of the believer. The explanation contains the promise: those who believe on Jesus will receive the Holy Spirit. This promise is, of course, for believers in Jesus. Believing is not the cause of the receiving; rather, the receiving is the cause of believing, for the Spirit creates faith through the Gospel.
The focus here is on the promise: we will receive the Spirit. That promise is worth taking some time to ponder and meditate on. God lives in us! God’s life dwells in my life! The Almighty God, Creator of the universe, has chosen to live in the hearts of believers and to influence their lives from within.
After Jesus was glorified, risen, ascended, and seated, He poured out the Spirit on all flesh, so that people can believe the gospel and be filled with God. In our daily interactions with people God is touching lives through us. Believing this promise makes us more careful about how we treat others.