One word will do it : Pride.

But more words more fun, so...

Pride, which is to say, a lack of faith. Pride is the opposite of humility. Humility is knowing you don't know. Living a life of humility in action is brotherly love. Brotherly love, combined with knowledge, is faith. Faith is not belief, and the word is being misused that way. Belief without faith is wrong ; faith without belief is nonsensical ; but the two are entirely different things. Faith is love and knowledge put together. In action, its forgiveness and charity - because knowledge is knowing that you know nothing, and if you know nothing, then the only valuable thing you can ever do is serve. But... I'm not making any assertions about what service looks like, nor even that you could choose not to serve, since I take it as an article of faith that all things serve the greater good. So I mean... Its all just how you choose to be.