Believers in Jesus Christ receive the indwelling of the Holy Spirit of God. When we walk in fellowship with the Spirit "rivers of living water" will flow forth from the believer.
The Words of Jesus are truth, and truth divides those who receive it from those who don't. In this passage we see the divisions Jesus provokes concerning the timing of God, the truth of His Word and the character of Jesus.
Jesus teaches on the need for one to "consume His flesh and drink His blood" in order to have eternal life. Understanding the lessons Jesus teaches through this metaphor.