Is it really necessary that a persons faith be organized into a religion...?
If you accept that there is a higher power than yourself and you require yourself to do the right, fair and proper things..etc.
Eh...just thinking out loud..
You'll probably see me post this again in the future.
God is a God of order. Everything we need to know as humans is in Genesis. He created the world in 6 days and rested on the 7th. To show that man was not created to work, but to worship Him. As well as to show that The Sabbath was created for man, not man for The Sabbath. Work came in the form of a curse after they ate of the forbidden fruit. Anyway, I'm getting sidetracked...
Everything man needed, was already provided by the time he was created. Air to breathe, animals for companionship and for caring, nature to enjoy and to tend to, fruits of all manner to eat and partake of. Fruits and vegatables were the original diet BTW. Not meat. That came after sin was introduced in the world.
Everything God does is done in order. He created the heavens and the earth, then the sea and then the trees/greenage, then the animals, etc. So too, should we worship. The Church is a body. aka the Body of Christ. Your eye doesn't look one way and you walk another way, that's a dysfunctional body. So too goes The Church.
The lack of "rules" as you put it is akin to free-for-all, which is not order, and is akin to chaos, which is not of God's will, as God is a God of order.
Hopefully you got the point.