God has given man an ability to speak and with that ability comes great power and consequence. Jesus even stated that one day believers will be judged for every idle word that proceeds out of their mouths (Matthew 12:36).
You can not get away from the law of confession; whether you are born again or you are lost. Your life is attached to your words. If you speak negatively over your life, you will reap a negative harvest. If you speak the Word of God or as I like to say the Word of your covenant over your life, you will reap covenant blessings. Your life is in your mouth.
We can see this concept all through the Bible. Genesis chapter 1 describes an earth that is void and without form. Then God steps on the scene and things begin to change.
As soon as God speaks, life and light begin to fill the Universe. Hebrews 11:3 declares that the world of Genesis chapter 1 was framed by the word of God. It is clear that God used His Word to form the Universe.
As beings created in His image, we have also been invested with the ability to frame our own worlds with the Word of God spoken by our lips. If you read the book of James in chapter 3, you will see that our tongues control the course of our life. Therefore we should be careful what we say because we will have what we say.