Well, here's the definition of ideology from the Random House Dictionary:

1. the body of doctrine, myth, belief, etc., that guides an individual, social movement, institution, class, or large group.
2. such a body of doctrine, myth, etc., with reference to some political and social plan, as that of fascism, along with the devices for putting it into operation.
3. Philosophy.
a. the study of the nature and origin of ideas.
b. a system that derives ideas exclusively from sensation.
4. theorizing of a visionary or impractical nature.

I would say that in common usage, "ideology" usually has a more negative implication. If you take this definition, then it would seem that almost everyone has some sort of ideology.
Whatever the case, the "sheep" are the ones likely to be in thrall of an ideology [religious or nonreligious], while more independent thinkers tend to pick and choose - and there are plenty of independent thinkers in religious denominations.
Yeah, I accept (generally) the body of doctrine of my Catholic Church, including the Scripture stories (liberally) - Catholic teaching is a rich part of my life. However, I don't think it has motivated me to do anything bad - I go in for feeding the hungry and clothing the naked and stuff. Not as dramatic as suicide bombing, and hardly something anyone would consider offensive. Actually, I live in serious right-wing territory, and we DO get strong objections to our attempts to feed the hungry and shelter the homeless. If my efforts are offensive, I offer no apology.
I believe in God, and I make no apology for that, either. I wouldn't define God, though. I think I like the practice of Orthodox Christianity, of using contradictions to define God. But for me, God is somehow wound up with all goodness and love and peace, and the innate unity and interdependence of all that exists. I can't really say I have much faith in absolutes - my beliefs in social justice and love and peace are about the closest I come to absolutes.
-Joe-