In the beginning God said "Let there be......." and it was so. Right away God was giving man a demonstration of dominion/authority. Now notice God said and it was so. And God said "Let us make man in our image and after our likeness" (Genesis 1:26). You are a spirit made in the image and likeness of God. And God said "Let them have dominion." God gave you an example of dominion everytime He spoke something it was done. He used words to get things done in the earth. And He made you like him and gave you what He had. So what does that means? Your words now get things done in the earth. You remember what the centurion said to Jesus in Matt. 8:8 "Speak the word only and my servant shall be healed" that's how authority works when you want something done you speak.
And all through The Bible God tells you about your speaking power. In Job 22:28 the word says "Thou shalt decree a thing and it shall be established." In Proverbs 18:21 the word says "Death and life are in the power of the tongue and those that love it shall eat the fruit thereof." In Ecclesiates 8:4 it says "Where the word of a king is there is power." And in Revelation 1:6 it says we have been made kings and priests. Now what do kings do, decree a thing and it is established/done. Another verse in Proverbs says "A man shall be satisfied with good by the fruit of his lips" (Proverbs 12:14).
Jesus said, All things are possible to him that believeth (Mark 9:23). Jesus also said "For verily I say unto you, that whosoever shall say unto this mountain, Be thou removed and be thou cast into the sea; and shall not doubt in his heart, but shall believe that those things which he saith shall come to pass; he shall have whatsoever he saith." (Mark 11:23) Your words get things done in the earth especially when your words line up with God's words. Because God said in Isaiah 55:11 "So shall my word be that goeth forth out of my mouth: it shall not return unto me void, but it shall accomplish that which I please, and it shall prosper in the thing whereunto I sent it." For God's word to return to him someone has to speak it. So speak the word and let it accomplish for you.