The reason that the words you speak to another person are so important is that they will stay in the mind of the person, continuing to either bless or curse the person through influencing his or her own self perception, depending upon whether the words are positive or negative. They will even extend either the blessings or the curses into the next generation because the words will be repeated as being truth either by being spoken again or through actions which fulfill the prophesy of the words.
Just one frivolous but injurious comment can stick in the mind of a person, producing actions of speaking similar verbal assaults onto other people, injuring again and again.
It never ends until someone comes to Me for complete emotional healing. Then I can heal the broken ego and stop the curses.
Now do you understand why I said that a father should not provoke his children to anger? The injurious words that proceed from the anger spoken to the child will stay in the mind of the child, producing angry thoughts, words and actions in the life of the child. Thus, the anger curses upon others are perpetuated.
My advice to, "Let no corrupt communication proceed from your mouth, only that which brings grace to the hearer," is the standard by which My children must adhere. You must speak words which build up and bless other people rather than tear them down and curse them.
You are My child in the earth. You are My representative in the earth. You are the image of My character in the earth. You must determine to choose to utilize the key of My kingdom which instructs My children to only speak words that proceed from My mouth, words that bless. The measure to which you bless others, you will be blessed. The measure to which you curse others, you will be cursed. That should spur you on to only speaking blessings.
Numbers 14:18-19; Matthew 12:36-37; Mark 4:22-25; Ephesians 4:28-32; James 3, the entire chapter.