It is sanctified (hagiazetai). Present passive indicative of hagiazō, here “rendered holy” rather than “declared holy.” Cf. 1Ti 4:4.
Through the word of God and prayers (dia logou theou kai enteuxeōs). See note on 1Ti 2:1 for enteuxis. Paul seems to refer to Genesis 1. It is almost a hendiadys “by the use of Scripture in prayer.”