How to protect your heart from your sinful nature

What is the difference between your heart and your sinful nature? The answer to this interesting question is a key factor in understanding what it means to be a faithful follower of Jesus Christ. After all, “The Lord does not look at the things man looks at. Man looks at the outward appearance, but the Lord looks at the heart” (1 Samuel 16:7).

The reason we experience sinful desires is because we have a sinful nature. Think of your sinful nature as the basement of your soul. The Apostle Paul wrote, “I know that nothing good lives in me, that is, in my sinful nature” (Romans 7:18). You see, the apostle’s basement room, like yours and mine, was full of evil. But the basement room was not Paul’s heart, and it was certainly not the apostle's intention to live his Christian life in the basement. 

Paul’s heart, like that of born-again people today, was committed to doing God’s will and serving his Lord and Savior, Jesus Christ. “For in my inner being I delight in God’s law” (Romans 7:22). As a forgiven child of God, Paul wanted to please the Lord with his thought life and his behavior. But like all of us, there were times when Paul entertained sinful thoughts, even if only for a minute. The Bible does not tell us how long Paul entertained these sinful thoughts in his heart, but Paul would no doubt renounce those thoughts and ideas shortly after they entered his mind. 

For example, Paul may have had brief lapses where he spent 20 to 30 seconds harboring ill will toward those who were persecuting him. But regardless of the specific temptations Paul wrestled with as a believer, he did not regularly give himself over to unwholesome thinking and ungodly behavior. If that had been the case, we would read about it in Scripture, and Paul would not have been in the mental and spiritual position to faithfully carry out the enormous mission God called him to complete. Simply put, the apostle’s walk matched his talk.

How else would Paul have been used by God to reach so many people with the Gospel, plant so many congregations, and write so much of the New Testament? Such a feat would have been impossible if Paul was continually allowing his mind to be dominated by sinful thoughts. Paul’s heart was on fire daily to spread the Gospel, reach the lost, and make disciples; whereas his sinful nature was the room in his soul he avoided with every once of his being. “So then, I myself in my mind am a slave to God’s law, but in the sinful nature a slave to the law of sin” (Romans 7:25).

How are things going today in your heart and mind? Are you protecting your heart from your sinful nature, or are you deliberately making trips to the basement room of your soul? Our calling as Christians is clear, namely, to “take captive every thought to make it obedient to Christ” (2 Corinthians 10:5). Whenever we are tempted to give into jealously, gossip, resentment, worry, lying, lust, a judgmental attitude and the like, God will give us the strength to resist going down into the basement. 

And for those times when we give into sinful thinking, we need to come to our senses, confess our sin to the Lord, and get back upstairs where Jesus is waiting for us in the living room of our soul. You see, Jesus never ventures down to the basement, but He always loves us unconditionally, even when we make poor choices that take our thought life in a wicked direction.

Filling our mind with Scripture is a powerful defense in our struggle against sin. Memorizing Bible verses and meditating upon God’s Word has been a source of tremendous strength for millions of believers over the centuries.

Whenever we do not protect our heart and mind from our sinful nature, we find ourself getting into the wrong “flow” mentally and spiritually. The flow of the Holy Spirit produces love, joy, peace, and godly thinking, whereas the flow of the basement room produces restlessness, agitation, and ungodly thoughts within the heart of a Christian. You and I were not rescued from sin and death so that we could fill our heart with sinful thoughts. We were saved in order to bring glory to the Lord by setting our heart and mind on things that are pleasing to God. And whenever we fix our thoughts on the Lord and on wholesome things, we discover that the flow of the Holy Spirit continues to fill our heart with godly desires and spiritual power.

God’s Word instructs us: “Above all else, guard your heart, for it is the wellspring of life” (Proverbs 4:23). Guarding your heart involves carefully screening what you allow through your eyes and faithfully filtering what you allow into your mind. How are things going today in that critical aspect of your life as a follower of Christ? When our heart and mind are in a good place, our Christian life flows with peace and power. But whenever we engage in unwholesome thinking, it upsets our entire life of discipleship.

This explains why Paul was inspired to write the following directive to Christians: “Whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable - if anything is excellent or praiseworthy — think about such things” (Philippians 4:8).

And not just on Sundays, but every day. Otherwise, your heart will suffer many things that could have been avoided by simply saying “no” to certain mindsets and particular attitudes.

A tall order? Definitely. And yet a noble thought life is essential in order to protect your heart from your sinful nature. 

What is the pinnacle of pure thinking? “Let us fix our eyes on Jesus, the author and perfecter of our faith” (Hebrews 12:2). Easier said than done, and yet it is the only way the Christian life works.

If you are a believer in Jesus Christ, your sins have been forgiven, and your heart now belongs to the Lord rather than to yourself. Therefore, “Fix your thoughts on Jesus” (Hebrews 3:1).