The heart is the seat of your personal life. It is the inner most part of your mind. From your heart proceed the issues of life: your inward thoughts, your desires, your belief, your service. That which is in your heart can be negative or positive: sorrow or joy, heaviness or hope, pride or humility, covetousness or willful giving, foolishness or wisdom, evil imaginations or the Word of God. You decide what you are going to think about and place in the depths of your heart.
1 Samuel 16:7
But the LORD said unto Samuel, Look not on his countenance, or on the height of his stature; because I have refused him: for the LORD seeth not as man seeth; for man looketh on the outward appearance, but the LORD looketh on the heart.
Shall not God search this out? for he knoweth the secrets of the heart.
Every way of man is right in his own eyes: but the LORD pondereth the hearts.
2 Chronicles 16:9a
For the eyes of the LORD run to and fro thoughout the whole earth, to shew himself strong in behalf of them whose heart is perfect toward him. . .
God looks at the heart. He knows what is on the inside. He is continuously checking out the heart of man - not to find fault, but to shew himself strong on man's behalf.
1 Chronicles 28:9
And thou, Solomon my son, know thou the God of thy father, and serve him with a perfect heart and with a willing mind: for the LORD searcheth all hearts, and understandeth all the imaginations of the thoughts: if thou seek him, he will be found of thee; but if thou forsake him, he will cast thee off for ever.
A perfect heart is a complete heart. It is a heart that is wholly devoted to God. It is a heart filled with the Word of God. It is a heart that exemplifies the first and great commandment:
And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment.
A perfect heart is a heart wholly devoted to keeping God's Word.
Thy word have I hid in mine heart, that I might not sin against thee.
David was a man after God's own heart. David hid God's Word in his heart and kept his whole heart focused on God. He encouraged Solomon, his son, to serve God as he had served - with a perfect heart.
1 Chronicles 29:19
And give unto Solomon my son a perfect heart, to keep thy commandments, thy testimonies, and thy statutes, and to do all these things, and to build the palace, for the which I have made provision.
David prayed that God would give Solomon a perfect heart and Solomon did walk for many years with a perfect heart before God. He did build the temple and God did give him an understanding heart filled with the wisdom of God. Yet before his life was over his heart was turned away from God.
1 Kings 11:4
For it came to pass, when Solomon was old, that his wives turned away his heart after other gods: and his heart was not perfect with the LORD his God, as was the heart of David his father.
David remained a man after God's own heart that loved God with his whole heart throughout his life. His example of keeping the Word of God with a perfect heart is shown beautifully in Psalm 119.
Blessed are they that keep his testimonies, and that seek him with the whole heart.
With my whole heart have I sought thee: O let me not wander from thy commandments.
Give me understanding, and I shall keep thy law; yea, I shall observe it with my whole heart.
I intreated thy favour with my whole heart: be merciful unto me according to thy word.
The proud have forged a lie against me: but I will keep thy precepts with my whole heart.
I cried with my whole heart; hear me, O LORD: I will keep thy statutes.
A perfect heart is a complete heart. It is a heart that is wholly devoted to God.
I will praise thee, O LORD, with my whole heart; I will shew forth all thy marvellous works.