If you believe in god, meaning that you have a personal relationship with god, what need do you have for religion?
Isn't it essentially other people telling you how you should have a relationship with god?
True religion is defined in the bible as "to keep one's self unspotted from the world and to visit widows and the fatherless in their affliction"
That translates to not sinning and making things better for others.
Sin is the transgression of the law -the law is from God and should not be changed by man -though it must be applied to various cases at times (such as with the system of judges of ancient Israel).
To not sin, one must keep the Ten Commandments (the first of which includes obeying various judgments which have changed over time).
That is HOW to have a relationship with God (though it becomes more personal and even interactive with obedience and prayer, etc. -as God said if we draw near to him, he would draw near to us.)
Most could agree with most of the commandments -as they would create a wonderful world if everyone kept them -but the principles behind even those which specifically mention God are valid even if a self-aware God did not exist.
Unfortunately, much religion today is people pretty much making stuff up and changing that which was given from the beginning.
Perhaps the most confusing part of the "biblical" religion recorded therein is that even that changed over time somewhat -but God was doing the changing thereof.
The commandments never changed, but various judgments changed drastically over time.
This must be viewed in the context of God making gods of semi-intelligent humanoids in the span of 7000 years overall (not that the earth is that old or that other species did not exist previously) -and in about 100 years of individual experience.
In other words, God created situations by those judgments -sometimes from unpleasant to horrible -in order to give us the necessary experience base and to create the wonderful future which will be.
All of our modern human history is a personal relationship with God -all declared beforehand for those willing to study (though some are unaware) -who said he would refine us and make us pure as fine gold -to the end that we inherit the earth and then the entire creation -and can then be trusted to not destroy it.
It seems harsh, but every creation is essentially made by exactly-opposite forces -so that wonderful future required that we experience and eventually reject and overcome the opposite.