We believe the Bible is the Word of God, and all our corporate activity is guided and directed by this alone.

Shorter Catechism Answer 2 " The only authority for glorifying and enjoying Him [God] is the Bible, which is the word of God and is made up of the Old and New Testaments."

Answer 3 "The Bible primarily teaches what man must believe about God and what God requires of man"

Subordinate Standards as set out in the Westminster Confession of Faith

Someone will write a fuller account about this and maybe even split it across several sections and multiple articles, with links for further reading.