Keep thy heart with all diligence; for out of it are the issues of life. Proverbs 4:23
READ: Psalm 119:10-12
10 With my whole heart have I sought thee: O let me not wander from thy commandments.
11 Thy word have I hid in mine heart, that I might not sin against thee.
12 Blessed art thou, O Lord: teach me thy statutes.
It is shocking how believers engage in all manner of conversations and associations carelessly. If you know the value of your heart, you would guard it jealously. In 2 Samuel 13 we see a classic case of what happens when a person does not guard his or her heart. Amnon who was prince and could have married any lady in the land lusted after his half-sister who was a virgin. He then engaged in a seemingly harmless conversation with a friend who watered the seed of evil already planted in his unguarded heart. The evil desire then blossomed and led to his untimely death in verses 28 and 29 of the same chapter. The man who advised him to rape his sister is the same one who announced his death to David, his father (2 Samuel 13:32). Choose those you associate with wisely (Psalm 1:1).
Be careful of whom you listen to and be mindful of what you let into your heart. Jesus said in Matthew 5:8:
"Blessed are the pure in heart: for they shall see God."
If you allow impurities to dwell in your heart, forget about ever seeing God.
In Matthew 12:34, Jesus said:
"... for out of the abundance of the heart the mouth speaketh."
In other words, your lifestyle and speech are an overflow of the meditation of your heart. Believers who listen to worldly music and also allow their children to listen to them are courting trouble. The result may not be instant, but it will accumulate and surely begin to yield ungodly fruits.
King David knew the secret to a clean heart, and he shared this in Psalm 119 :11:
"Thy word have I hid in mine heart, that I might not sin against thee."
Meditating on the Scriptures, listening to recordings of sound teachers of the gospel and keeping company with fellow believers are some of the primary ways through which we can keep our hearts guarded. You can only express what you have in your heart. Thus, if you constantly expose your heart to God's word, you would guard your heart from all forms of ungodliness. Motivational words cannot cure sinful thoughts, only the word of God can.