Without engaging in the kind of deep discussion that mr Porretto employs, (mostly because I’m incapable) here’s my Og take on religion.

Most of us are judeo-christians. Most humans, that is.

The God of Abraham, in an era of polytheism, became the One True God, and Jews were the True believers.

Schisms occured in the Hebrew faith, and each of the splits became the True believers.(Yes, I know this is a gross oversimplification, shut up- I’m making a point)
Christianity came along, only at the time it wasn’t christianity, it was judaism with Christ as a great and powerful spiritual leader, and THOSE people became the True Believers. Later, a mad pedophile staggered in from molesting sheep and declared himself the Prophet, much in the way Mikey Jackson declared himself the King of pop, and Mahomet’s followers became the True believers, and all else were unfaithful to the God of Abraham (infidels. get it?)of course, then they divided to become sunni, sufi, shiite, etc, each of which were the True believers. At each split there are groups of people who belive that they have found the perfect way to believe, and people who are sure the other people are wrong.
Christianity, being the most exploitable belief at the time, was turned into a political business, and it ruined a lot of lives. At one point the roman rite and the eastern rite split one from another. At one point, the Pope was so corrupt as to drive people away from him and to Martin Luther in crowds. Martin Luther removed chunks of the bible because those chunks made it clear his little reformation was not exactly kosher, and with less of the bible, declared himself to be the leader of the One True faith. Later, calvin and his followers decided that all of christianity up to that time was flawed, and Calvinisim became the One True Faith.

Let’s recap: Several types of judaism,Christianity, Islam, each claiming to be the only sect/group/church that Knows The Way. Hmmm.

Let’s simplify this:

You don’t know.
You cannot know.
You can only take anything on faith.
Anytime anyone tells you that you should despise someone else because they are a different faith, their (personal) faith is inherently flawed.
Anyone that says you should kill someone because their faith differs from you is deranged and must be contained or eliminated. Murder and faith in the creator are mutually exclusive.

Facing this uncertainty, there is only one course of action.

Don’t be an asshat. That’s right, try to be a decent person. Treat your neighbors with some respect. Have courtesy for people you don’t know, perhaps even people you dislike. Try to show what kind of human you are by your actions. Try to be kind, considerate of others, raise your children well. Speak ill of nobody. Judge no one. Let other people have their beliefs, and if you disagree with them, see if you can win them by your actions. Heated debate invariably distances more people than it brings together.
If you are in the habit of knocking on doors to try to convince me that being a Baptist/Jehovah’s witness/seventh day adventist is the One True Way to acheive salvation, especially if you’re going to tell me/my wife/my child that we are going directly to hell because we’re catholics, be prepared to leave in a large hurry. Debating about who is the One True believer is simply partisanship, and in fact is the core problem of religion, and has been, forever. My god is better than your god, or my way of worshipping him is better than your way, has been the cause of nearly every act of ungodliness that has existed since Cain slew Abel.

Go in peace. Shit, just go.