"If we say 'I believe in Jesus' but it doesn't affect the way we live, the answer is not that now we need to add hard work to our faith so much as that we haven't truly understood or believed in Jesus at all"
(Prodigal God, p124).
Unless theology actually affects our lives and the way we live, then we obviously don't believe it. We may say we do. We may even want to. But the way we live our lives reveals our true belief structure; we deceive ourselves. I want all sorts of things to be true about me. I say I value all kinds of different concepts and ideals but unless they actually work themselves into my life they are only ever ideals and not the reality of how I live my life.
At this point it would be very easy to point fingers at various people but we're all guilty of playing the hypocrite. It's the one thing all humans do well. That's were community comes in: friends, spouses, children, even the person you only talk to Sunday mornings while eating cookies. God gives us each other, in part, to speak truth into each other's lives. I rationalize all sorts of behaviors and actions. Often I have no clue I'm even drifting (If I knew I was self-deceived... then I wouldn't be deceived). God places brothers and sisters in Christ into our lives to speak truth to us, even when it hurts, and expects us to have knee-jerk reactions of self-reflection and mutual submission rather than defensiveness and aggression.