Q: What rule hath God given to direct us how we may glorify and enjoy him?

A: The word of God, which is contained in the scriptures of the Old and New Testaments, is the only rule to direct us how we may glorify and enjoy him. (1)

(1) Galatians 1:8-9. But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.

Isaiah 8:20. To the law and to the testimony: if they speak not according to this word, it is because there is no light in them.

Luke 16:29, 31. Abraham saith unto him, They have Moses and the prophets; let them hear them... And he said unto him, If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.

2 Timothy 3:15-17. And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: that the man of God may be perfect, throughly furnished unto all good works.

(From the Westminster Shorter Catechism)