Whoever believes in Me, as the Scripture has said: ‘Streams of living water will flow from within him.’ ”He was speaking about the Spirit ~ John 7:38-39 Berean Study Bible
(Quote from https://realreality.org/downloads/how-god-will-transform-you/)
When God gives you His faith, you’re born into God’s Kingdom by the springing fountain of the Holy Spirit. Your spirit changes as it unites with the Holy Spirit.