Mark,

Psa 119:11  
I have hidden Your Word in my heart, so that I might not sin against You. 

As good as the writer of Psalm 119 has it the application of God's Word to effect change required much effort. I'm not suggesting it wasn't a profitable exercise. I believe it was. It just wasn't as good as what was to come.

Jer 31:33b  
... After those days, says Jehovah, I will put My Law in their inward parts, and write it in their hearts; and I will be their God, and they shall be My people. 

I just love the "I will put" and "I will write" language. Sanctification is sooo superior in this age. 

2Co 1:21-22
But He confirming us and anointing us with you in Christ is God.  (22)  And He has sealed us and having given the earnest of the Spirit in our hearts.

Grace!
  Moe