Most of my problems involve my mouth. I am contemplating the sins of my own mouth- trust me there are more than I'd care to admit. Here is a list of Biblical sins that come out of the pie whole!
Lying and Deceit- Some people think everyone does it and so it is okay. Really? Jesus didn't see the need to inflate the truth, make himself more spiritual than he is, or flat out lie about something. To the extent that I practice deception I am not like Jesus!
Gossip and Slander- this is speaking about others when it is not my business. Whether it is true or not, if it is not your business, then you shouldn't speak of anothers business to another. You are always free to confront another believer about godless behavior (though we seldom do!)
Boasting- This is of course motivated by our pride... need I say more?
Profanity, swearing, cursing- though they are different from each other they pretty much take all that is holy and drag it through the mud. Profanity makes common the holy; swearing is an effort to insure the truthfulness of your words by calling on holy things, and cursing is calling upon a holy god to "damn" things.
Complaining- yeah we don't "do everything without complaining and murmurring" do we?
Contentious words- you know looking for a fight or a controversy. Causing discension or confusion in other believers minds, maybe even causing division amongst brothers.
Destructive words- speaking things that don't build up, edify and make strong.
Eph 4.29 Do not let any unwholesome talk come out of yoru mouths... and do not grieve the Holy Spirit!