There's power in the Truth. Truth is power. God's Word is Truth.
If we are not speaking God's Words, we are not speaking the Truth. We are speaking the worldly words, maybe half-truths. We are speaking the wrong words, not the right words.
Speaking God's Word cannot be done haphazardly or in haste. Once we have plowed up the stony ground in our heart, removed all the distractions, and are prepared to receive the revelation that God is going to bring forth in our life ... new manifestations of His love, faith, power, and revelation knowledge will start to spring forth.
But until we do these things, we will not recognize these manifestations which must be mixed with faith. Then we have to expect God to begin a new work in our life.
Reverend Robert W. & Mary C. Butler