Hebrews 4:12-13 is a beautiful paradigm of what the word of God is, God’s revelation of Himself to us through the written words of the Bible and through the living word Jesus. As the written word is able to pierce and the living word is able to open and lay bear, God confronts, informs, calls and relates to us. John 14 further clarifies the ministry of Jesus as the Living Word in that as the Holy Spirit lives in us, the life of Jesus reveals the Father to us. Pretty cool, a (the) way to enter into vital relationship with the living God of the universe.
We trust the testimony of the written word because it is inspired, efficacious and practical for guidance in life. We find that it speaks truth to us. So we embrace learn and walk in it. What a journey.