The primary reason God's word can have such an effect on a believer's life is its vital association with the Holy Spirit.

Father, You sent Your Holy Spirit to be a Counselor to me.  He came straight from You to me and other believers.  He is the Spirit of truth who goes out from the Father, and He faithfully testifies truth to me concerning Your Son, Jesus (John 15:26).

Lord God, sanctify me by the truth; Your Word is truth (John 17:17).  Please help me to embrace fully what this verse is saying, Lord.  I can be saved by You, but if I don't allow You to teach me and mature me through Your Word, I will never fulfill what You sanctified or set me apart in this earthly existence to do.

Father God, You have no greater joy than to hear that Your children are walking in the truth.

(from Beth Moore's Praying God's Word Day by Day)