You can speak one thing and believe another in your heart. Your words must be in alignment with your heart in order to see results. You have no power in your words if your heart is focused on the opposite of what you are speaking. The word of God says that they cry Lord but do not obey my commands. How is this possible?
It is possible because it is the condition of the heart that God is listening to. When your words are confessed there cannot be a shadow of doubt (fear) that it will not come to pass.