The battle of the mind and the mouth is so difficult to overcome.
We're told in the Word to take every thought captive to Christ, but do you ever just get mad and not want to do that? Yeah, me too... more than I care to admit. I allow those ugly, not good thoughts to fester and at some point the filth spills out of my mouth into the air and I'm left wondering how I could have failed in my words... again.
No matter how tired we get, we need to depend on God's grace and help to not even think bad things, because once the thoughts are there the actions surely follow.
Let me tell you that I have to pray about this A LOT. I'm a very emotional, wear-your-heart-on-your-sleeve type of person and keeping my thoughts and opinions to myself is very difficult so I doubly have to watch my mind. I have not mastered this at all, but I have learned a few things.
One thing I learned is if you're thinking something rude or wrong or bad, sleep on it. Pray about it first and then leave it until the next day. If after prayer and some sleep (sometimes, ladies especially, we are just exhausted. Don't be afraid to take a nap.) you still think this is something worth saying and thinking about, then continue on in grace not with a hypocritical, rude, or mean attitude.
The second thing I have learned/am learning is not all thoughts need to be voiced. Sometimes it's a prayer sent up telling God alone what's on your mind and heart and sometimes it's worth journaling about, but telling your family, your husband or wife, your girlfriend or boyfriend, your best friends about what's bugging you can easily turn into a complaint, "here's what's in my head" ordeal. Be careful.
The third thing I have learned is to dwell on Truth. Read God's Word. If what you're thinking lines up, continue on. If not, reject it and find a verse or a prayer to think on. I promise this helps so much with the battle between the mind and the mouth because you'll find you slowly are becoming more like Christ because you're getting to know Him more.
Finally, pray for help in the battle. Pray for His help thinking pleasing thoughts and saying pleasing things.
Alone we cannot overcome, but through Christ victory is ours.
"Look to the Lord and his strength;
seek his face always."
- 1 Chronicles 16:11