My final word on this subject must of course come from The Word. Of course, you don't have to look far for biblical references to this subject. Jesus said that He is "the Way, the Truth, and the Life". If Christ is Truth, then it follows that lying must mean you are moving away from Christ. Being honest is about following in God's footsteps, for He cannot lie. My goal as a Christian is to become more God-like and God-centred, then honesty needs to be a focus. And that's honesty to myself as much as to my peers.
Exodus 20:16 - You shall not give false testimony against your neighbour.
However, being honest is not always easy. It's so easy for man to wander off the narrow path, and kid yourself that you're still on course. Therefore, you need to work at being truthful, and it is often pretty hard work. We need to keep our eyes on Jesus all of the time.