Acceptable Words and Meditations

The law of the LORD is perfect,
reviving the soul;
the testimony of the LORD is sure,
making wise the simple;
the precepts of the LORD are right,
rejoicing the heart;
the commandment of the LORD is pure,
enlightening the eyes;
the fear of the LORD is clean,
enduring forever;
the rules of the LORD are true,
and righteous altogether.
More to be desired are they than gold,
even much fine gold;
sweeter also than honey
and drippings of the honeycomb.
Moreover, by them is your servant warned;
in keeping them there is great reward.

Who can discern his errors?
Declare me innocent from hidden faults.
Keep back your servant also from presumptuous sins;
let them not have dominion over me!
Then I shall be blameless,
and innocent of great transgression.

Let the words of my mouth and the meditation of my heart
be acceptable in your sight,
O LORD, my rock and my redeemer.

-Psalm 19:7-14

How does one ensure that the words of his mouth and the meditations of his heart are pleasing to the Lord? By grounding himself in the Word of God.