Keep your heart with all diligence, For out of it spring the issues of life, Proverbs 4:23 NKJV.
For God to give out a clear instruction to guard your heart with all diligence, it means that there is something important about the heart of the Christian that he needs to be conscious of.
As a Christian, if you need to guard your heart, how would you go about doing this and from what would you need to be guarding your heart from? Our opening scripture from the Good News Translation gives a better light on this and it reads; "Be careful how you think; your life is shaped by your thoughts."
That is how you guard your heart, by being careful of what you think, which is your thoughts. You must be cautious and careful of the thoughts you have or allow. Don't entertain carnal and wicked thoughts that are not of God; don't give an opportunity of fellowship with demons, through wicked thoughts.
So then, what do you do if such a thought would come? You would need to respond out loudly and speak to yourself by saying, "No! I refuse to have this thought. I refuse to accommodate it." Practise this when the need to do so comes. And afterwards, don't go on and try to entertain the thought again. Don't be making an effort to be entertaining the devil.
It is very important for you to keep your heart and mind clean and pure and filled with thoughts of glory, grace, beauty and righteousness. As our theme scripture puts it, "...For out of it spring the issues of life." Your life is shaped by your thoughts, the thoughts that fill your heart. That is why when a person commits a bad or unpleasant act, it did not just happen, it started quite a while ago when it was created in the mind.
That is why it is important that you stop and reject bad thoughts while they are still at an early stage - the concept phase.
Therefore, if this can happen in one's heart, it means with the same heart, you can be a success and you can walk in prosperity. With your heart, your cell, fellowship or church can grow in membership. All you have to do is create it in your mind first. Therefore, it is of utmost importance that you fill your mind with the word of God. When you do this, you will only have word based thoughts and that is the direction your life will take.
Confession:
My heart is pure, blameless and clean. I think holy and righteous thoughts only. With the Word of God in my heart and mind, I create circumstances which favour the course of my life. Hallelujah.
Further study:
Proverbs 23:7 NKJV
Romans 12:2