We know our spirit is strong by what we are saying.  Whatever we are saying we are giving the devil an opportunity to get in our affairs or by our words we are opening the way for the Lord to move supernaturally in our affairs.  If we talk sickness and tell all the ailments and talk the problem we are opening the door for the enemy and telling the enemy of sickness and disease to come right in.  We are doing it with our mouths.  We must learn to give the enemy no place with our mouths.  If we slip then we repent quickly and bind and render powerless every contrary word to the Word of God. You can tell the condition of a person's spirit by what is coming out of their mouth for out of the abundances of the heart the mouth speaks or leaks.  You can see where a person is spiritually right away by just spending a little time talking to them.  Again, from the abundance of the heart the mouth speaks.