On the last day, the climax of the festival, Jesus stood and shouted to the crowds, “Anyone who is thirsty may come to me! Anyone who believes in me may come and drink! For the Scriptures declare, ‘Rivers of living water will flow from his heart.'” (When he said “living water,” he was speaking of the Spirit, who would be given to everyone believing in him.) John 7:37-39a NLT
The Feast of Tabernacles occurred about the first of October. The harvest was over, or nearly over, and the time for fall planting was near. The dry season had prevailed throughout the summer, and now it was time for the early rains, the fall rains, to begin. One of the great rituals of the feast was the bringing of water from the Pool of Siloam which stood at the bottom of the city where the Hinnom Valley joined the Kidron Valley up through the old city of David into the Temple precincts, where it was poured out to Yahweh.
The Israelites understood what we all know: where there is no water, there is no life. Cosmologists, hoping to find life forms elsewhere in the universe, look for signs of water on Mars, because they know that where there is water life might exist. But where there is no water, there is no point in looking further for life there.
It was in that context that the Galilean preacher, Jesus of Nazareth, standing in the Temple courts, cried out the words printed above. What was he saying? He was making the thoroughly shocking claim that he was the source of all that is necessary for spiritual life to exist. Really? Really! If the water of Jesus, the Holy Spirit, has flowed into you, and his presence is demonstrated by his life flowing out of you, you are really alive. But if your knowledge of Christ is only intellectual, or if your relationship with him is only one way: incoming, then there is real reason for concern. Life springs up where there is water flowing out. In the desert even if no water is visible, the Bedouin knows that if there are trees and bushes growing, then he can dig down and find water.
You and I have to ask: is Jesus, the water of life, so in me that living water is flowing out? If the evidence is not there, we must ask him, beg him, to pour himself into us. He longs to do it.