This is from a church friend Carol, it's pretty good analogy =)

"Non-Christians will probably never read the bible, so we as Christians are to be a living bible for them to read, everything we do and say can show whether we are living by God's word.."
That's why it is important to not swear or do anything bad that makes God's name bad.. it's not the act that is bad itself in some cases.. but it is the affect it has on other people and their perspective of a Christian.