Here "word of God" and "prayer" are used together to express one idea. The prayer is in agreement with the truth that God has revealed. Alternate translation: "it is dedicated for God's use by praying in agreement with his word" (See: [[rc://en/ta/man/translate/figs-hendiadys]])
This can be stated in active form. Alternate translation: "we sanctify it" or "we have set it apart" (See: [[rc://en/ta/man/translate/figs-activepassive]])