Christians are to be in union with Christ. This explains why it is so important to study the Bible, to meditate on it, to spend time trying to understand it, to communicate with one another with the Word and with the Father. What are we doing as we absorb God's Word? God's Word is part of His mind, His personality, His character. It is the way He thinks.
We cannot be in union with someone we do not know or who we have no relationship with. We cannot be in union with someone we never think about.
The more we think about Him, the more we carry His word in our mind. The more experiences that we have with Him, the deeper, stronger, sharper, clearer, and more real the union becomes. It all pivots around the Word of God. Jesus says, "The words that I speak to you are spirit, and they are life" (John 6:63).
They are an invisible force and power because, if we believe His words, they begin to work in our lives because we use them. They begin to produce what God intends them to produce. As we use them, we become more one with Him because we are becoming like Him. Our lives begin to be operated by His mind expressed in His Word. The more we use them, the more we become like Him.