Good question.

Religion means different things to different people. It's one of those words that even the scholars don't agree on, so no simple, dictionary definition is going to be authoritative. Most people on this site seem to think it necessarily encompasses supernaturalism, but history says otherwise. [agnostic.com]

In my personal view, science is about describing the natural world, and religion, in its authentic (not corrupted) form, is about describing ways to conduct one's life in a world that is no longer like the world we were evolved to live in. We have changed our environment radically in the last twelve thousand years, and we can no longer function as "natural" animals. If we are to continue living in the civilized world, we will continue to need to modify our natural instincts that direct us to "live by ego". And it is religion's job to supply that training - no supernaturalism required, only directed practice.

Science is the best source of knowledge. Religion (if it is to stay relevant) needs to be the best source of wisdom. It has served that purpose in the past, and we still very much need it to continue. But it will need to submit to some long overdue reform.

Doesn't sound very realistic to me.