1. The Effect of the Mind
Proverb 4:23 - Keep thy heart with all diligence; for out of it are the issues of life.

2. Translations for Proverb 4:23
Contemporary English Version - Carefully guard your thoughts because they are the source of true life.
New International Version - Above everything else, guard your heart. It is where your life comes from.
New Century Version - Be careful what you think, because your thoughts run your life.

3. Why guarding? Heart is the center of intellect, emotion and will.
Heart and mind are interchangeable.
It points to soul or personhood
Examples:
Saul: I Samuel 18: And the women answered one another as they played, and said, Saul hath slain his thousands, and David his ten thousands.
 8 And Saul was very wroth, and the saying displeased him; and he said, They have ascribed unto David ten thousands, and to me they have ascribed but thousands: and what can he have more but the kingdom?
 9 And Saul eyed David from that day and forward.

4. Ahithophel: II Samuel 17:1-2 – 1 Moreover Ahithophel said unto Absalom, Let me now choose out twelve thousand men, and I will arise and pursue after David this night:
 2And I will come upon him while he is weary and weak handed, and will make him afraid: and all the people that are with him shall flee; and I will smite the king only:
His granddaughter: Bathsheba
Diotrephes: III John 9-10 – 9 I wrote unto the church: but Diotrephes, who loveth to have the preeminence among them, receiveth us not.
 10 Wherefore, if I come, I will remember his deeds which he doeth, prating against us with malicious words: and not content therewith, neither doth he himself receive the brethren, and forbiddeth them that would, and casteth them out of the church.

5. How can we guard our hearts?
Paul: I Timothy 1:15 - This is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners; of whom I am chief.
How can we guard our hearts?
Proverb 23:7 - For as he thinketh in his heart, so is he: …
Philippians 4:8 - Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.

6. How? True: opposite of dishonest and lies
Honest: honorable, worthy of respect and reverence
Just: conformity to God’s standard; righteous relation between man and man and between God and man
Pure: not mixed with moral impurity; chaste
Lovely: lovable, beautiful, pleasing, gracious, promoting peace
Good Report: worth talking about, what is positive
Virtue: excellence
Praise: praiseworthy
How?
John 17:17 - Sanctify them through thy truth: thy word is truth.

7. Modern example Kimani Nganga Maruge in Kenya
World’s oldest student died at 90
Oldest of seven children
Law passed for free access to primary education
Started school at 84 after being rejected 5 times
His goal; reading the Bible
Relocated and yet went to school 2.5 miles one way
Dropped out when he had a cancer

8. New Century Version - Be careful what you think, because your thoughts run your life.