Have you ever watched a river rush by? And have you ever stood in a rushing river? Depending on what river you're looking at it it might appear calm and slow, but when you stand in it and feel the current go by it can be a dangerous thing. There is real power there, power to destroy and power to do good things.
Two creeks meet in our pasture. The picture at the top of this page is a picture of them. I took that picture a few summers ago. Since then they have changed appearance quite drastically in places from spring snow melt floods.
My oldest son gets a jar of creek water for his science class. They look at it under microscopes. It is full of life -- but not good life.
One summer the kids swam in the creek almost daily (some places it was five feet deep that summer). I'd make them shower quickly when they returned home.
Now, look at the verse above. Believers have living rivers flowing out of us. Most likely most of us can't feel those rivers but that doesn't mean they aren't there. Jesus said they were so they are. We might not feel them but we should see evidence of them if we're letting them flow out.
Okay, now, here's a thought. We can also hinder that powerful living water from flowing out of us to our worlds. How? Unbelief, Discontent, Fear, Human Anger, Envy, Bitterness, Sin. All these will stop up the flow. The river is still there but it can't flow unhindered when we fill it full of junk.
Clean out your rivers (yes, it said rivers, not river). Let those powerful bodies of water rush out of you.