Jesus disciplined His mouth. He refused to say anything other than what God said. And then He instructed us to do the same.
Now it's very tempting to say something out of emotion at a time of crisis. It will do you good to know what to say in that day. If you must say something, open up the Bible and find out what to say. Say that instead of what you feel like at the moment.
The reason why Jesus wasn't speaking anything other than what God said was that He did not want to mess up the deal. To avoid saying the wrong thing, He put a guard over His mouth. Now you need to put a guard over your mouth, because death and life is in the power of the tongue.
The words you speak are very important. They are vital to God being able to work in your life. James 3:2 says, For in many things we offend all. If any man offend not in word, the same is a perfect man, and able also to bridle the whole body. (KJV)
When you say I can't help myself, you can't. When you say I can't do it, you can't. When you say I can't see how, you won't. When you say nobody is going to help me, they won't. He said the man who doesn't sin in words is able to control his body. You may say, "You mean my body responds to my words?" Yes it does.
Jesus didn't offend in words, therefore He kept His body in line. That means then you have to talk to your body. Don't wait for an emergency. Tell your body you are healed today, and you are going to stay that way. I talk to my body every morning. I tell my body, "You are healed from the crown of the head to the soles of the feet." And then I list every body part, and tell it that it's healed. And then I tell my body, "Body, you will live in divine health all the days of your life."
I've said all this to say: you need to take preventive medicine everyday. That is what it means to walk in victory. That is what it means to maintain Satan's defeat. That is what it means to follow the faith of God.
Scripture References: Proverbs 18:21; 1 Peter 2:21-25