Jesus says we are to believe in the written WORD of God. And by trusting in His word we have our breakthrough in Him.
JOHN 1: 1 - 3
In the beginning was the WORD, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through Him, and without Him nothing was made that was made.
It's amazing reading this scripture and it's so powerful at the same time.