McBell
Unbound
In a nutshell, religion is a reliable vessel for a message of truth to be conveyed throughout a history of more than 2000~3000 years. You won't be able to find another mean for such a message to be conveyed more reliably.
Humans on the other hand, rely almost exclusively on human witnessing to reach a truth of any kind. Humans themselves may not realize this though. So in order to be a god, one must know clearly how a truth can be conveyed through human witnessing and with a history of more than 2000 years.
He also need to know that humans won't be able to keep first hand documents longer than 2000 years that a religion is the only way for such a truth to be conveyed. As a matter of fact, humans lost all the documents written first-handedly in ancient scrolls for history older than 2000 years.
He then also need to specify strongly that "you shall not do false witnessing" such that humans are educated by the dogma of such a religion to realize that they shouldn't add anything by their own will to the Bible of the religion.
He then also need to build a human authority to enforce the passing on of the Bible in a way to keep it as intact as possible (i.e., the Jews won't add anything to the Bible lightly as they have the temple court as the only authority, similarly the Catholic and Protestant Church are doing the same).
Only then a message of truth can be passed along reliably for more than 2000 years.
Only the Christianity God does the above which makes Him the only possibility if a God does exists!
In the end, the essence of a true religion is to serve the purpose of conveying the message of salvation among humans throughout a history of more than 2000 years that no other means shall work!
The vast number of denominations reveals this to be at best wishful thinking and at worse a bold faced lie.