Religion is not the actual relationship with God, nor does it replace such. Religion is defined as merely the consensus of creed (or expression thereof) in which a group adheres to.
One other thing that we forget is that while religions exist to explain purpose or to hold to a creed, it isn’t the God Himself. So therefore man develops many expressions of religion to attempt to sooth our craving and appease our devotion. Yet these different beliefs can diverse and contrast. So it demands to determine which one is correct.
We can choose our religion or belief, which is our personal preference. We can even put our belief in a certain prescribed deity or to many gods if we want, which is also subjective to our preference. However, we cannot choose what is true. That is determined whether we know what it is or not.
Can all these co-exist?
Some think it noble to accept every belief as true. They believe what is true for you is different than what is true to another so we can believe all as true (this concept of “what is true to you…” and “all is true” is a branch of existentialism and actually is counter to logic). However, not every belief can exist as truth at the same time as another no matter what we prefer. They can contrast and cannot co-exist as both being correct at the same time.
In the most obvious example, Monotheism and Atheism cannot both co-exist as truth at the same time. One believes a Supreme God ultimately is responsible for creation existing outside our measure, while the other denies existence of that Being and thus man himself exists and was created by a mishap of accidental cause due to the natural reaction of nature. You cannot both believe in God, and deny Him at the same time claiming both is true at that moment. They contrast. One (or both) has to be false.
The same can be said for Monotheism and Polytheism. The belief of one God over the universe (monotheism) taking up space in all all himself as the Supreme Creator of it cannot co-exist with the concept that many gods exist (polytheism) at the same time to share in their place in the universe. Both existing as truth at the same time contrasts.
So can we get along and co-exist?
The Atheist can exist with the Monotheist… to a certain extent. When it comes to moral code one adopts the moral code of the Bible, while the other denying the Bible comes up with what he thinks is a universal humanitary code. That code usually does dovetail that which is on our conscience (written in our heart by God, but who’s splitting hairs of original authorship). However, the Atheist can stray to his own measure without conscience conviction. What happens when the worldview of one contradicts the other? Who’s is enforced? An Atheist may adhere to Survival of the Fittest (Evolutionary concept where nature determines the strongest survive) that doesn’t regard all human life equally. A Christian may regard all life equal in regard to God. One may determine life of a child is ONLY considered if the baby is born and the choice of life determined by decision, while the other may believe conception of a child originates in the womb, and that fetus is a child developing from conception.
So a lot to consider when we try to justify all as truths and equalize all beliefs as the same or co-existing.