Living water.

Of all the things in the world water is comparable to spirit as it is so pure & essential to life. Physically we are dependant on water, and spiritually we are dependant on spirit (or living water). 'God is spirit' so spiritually we need God. Spiritually speaking we are all thirsty if we do not have God inside us.

Jesus is offering the water that "will become in him a well of water springing up to eternal life." With normal water we drink it and then will get thirsty again, this living water is the opposite, it is an eternal supply. In the world we seek satisfaction for our physical desires, but such satisfaction is only temporary - the solution to becoming eternally satisfied is to take the living water Jesus is offering then we will find within ourselves a well of living water (i.e. God).