“For My people have committed a double evil:
They have abandoned Me,
the fountain of living water,
and dug cisterns for themselves,
cracked cisterns that cannot hold water.”
When a man watches the birds and foolishly tries to fly like a bird by flapping his arms as he jumps out of a tree everyone who sees him knows he is, in only a second or two going to suffer the consequences of his stupidity.
If a man wants to become a doctor and spends his time talking like a doctor, acting like a doctor, dressing like a doctor, and even writing like a doctor he will still only be a poor imitation at best. The only way to become a doctor is to go through the process of education and certification!
If a man wants to be a Christian and then spends all of time acting like a Christian, talking like a Christian, dressing like a Christian (whatever that might be) he will be only a poor imitation at best. The only way to become a Christian is to go through the process that Jesus established based on His sacrifice. The Bible says "without faith it is impossible to please Him." So you can do everything He wants you to do, but if you leave out "faith" you only have cistern and not a fountain of living water.
We have an old cistern at our house. It still holds water, but I wouldn't drink that water. It is stagnant and nasty and I'm sure would make me very sick. After a while the best cistern has water that you really don't want to drink.
When you are young and strong you may think you don't need the living water. Part of the wisdom of age is realizing that depending on God is the only hope you have left. Put a lid on your cistern and go to the "fountain of living water."