Jay Adams has defined the heart as the whole inward life lived before and known only by God and the individual.  Jeremiah the prophet wrote, The heart is deceitful above all things and desperately wicked; who can know it?

I remember that as a youngster, teenager, and professing Christian, my mother would often remind and admonish me to be involved in the right kind of activities or outward actions for the Lord’s sake.  I would often respond; Well, the Lord knows my heart!  And know my heart He did,…….it was deceitful above all things and desperately wicked.

I have long since become a Christian and as a believer my heart is now the dwelling place of Christ by faith (Ephesians 3:17).  That fact however, does not guarantee that my heart will not stray from my Saviour who lives there.  I must keep my heart.

My son, attend to my words; incline thine ear unto my sayings.  Let them not depart from thine eyes; keep them in the midst of thine heart.  Keep thy heart with all diligence; for out of it are the issues of life.          Proverbs 4:20-23

The challenge for the believer is the keeping of the heart.  My outward service to the Lord will be powerless and meaningless if my heart is not kept.  My son, forget not my law; but let thine heart keep my commandments.  Proverbs 3:1

How do I keep my heart?  By obeying God and by hiding His word in my heart.  He has provided the resource (His written Word) to keep my heart.  I must act by faith on that resource.  

Thy word have I hid in my heart, that I might not sin against thee. Psalm 119:11

What are you hiding in your heart?

…let the word of Christ dwell (take up its life) in you richly…