Believing in anything requires faith so they are not mutually exclusive. There are scientists who believe that science can prove the existence of God. Personally I believe what I want to believe depending on what mood I'm in.
Leftwingers these days are religous types. Political correctness is a form of silencing the Heretics from spouting blasphemey. Science invites Critisiscm to improve ideas.
It is possible to be a rational person and still be spiritual. I believe in the 'soul' and other things that science can't yet explain but I'm not religious.
Religion gives you the excuse to go out and kill as many people as possible who dont worship the exact same sky monkey. Science allows you to do it more efficiantly by inventing Nukes say...............
At the end of the day, if you believe in something that gives you comfort when say a relative or friend dies or is seriously injured or terminally ill, then there is nothing wrong with that whatsoever. If you believe that a book provides moral guidance on how you would like to live your life or how you would treat or have other treat you, then fine.
If you believe that science explains the mysteries of how we came to be here or, how something as supremely complicated as the human body works then again fine.
Its very trendy and clever to rubbish religion and people who hold religious beliefs, because we have so much strife in the world that is caused in some way in the name of religion ( or your particular type of religion) and also religion tends to be a be and end all belief.
At the end of the day, when you die, you will find out if there is a God, unfortunately you won't be able to tell anyone about it, therefore as I said its a matter of faith.
It is interesting how many religions have the idea of a great crossing when you die...crossing of a great lake in Norse mythology, crossing into heaven ( or hell) in the Christian and Islamic religions. scientifically I suppose you could argue that as the brian shuts down, it releases chemicals that aid death...maybe that is what poeple are getting at.