Many of us believe the biggest threat to genuine faith comes from charlatans who deceive with lies and half-truths, tickling our ears with what we want to hear. And certainly we must remain vigilant against those who preach a false gospel and seek to devour the gullible and vulnerable. But an equally dangerous source of deceit lies in our own hearts. In fact, the Bible tells us, “The heart is deceitful above all things and desperately wicked; who can know it?” (Jeremiah 17:9, NKJV).

According to this verse the heart has two defining attributes: it is deceitful and it is desperately wicked. Both traits represent sin that pushes us away from God and His love. And the two work quite well together. Deceit leads us to embrace doctrines and creeds that rationalize sin and justify whatever pursuit our heart desires. It subtly twists the truth of Scripture to convince us we are obeying God when in fact we are not. So powerful is the heart’s deceit that even in the midst of sinful behavior we insist we are in God’s presence.

Sadly, that treachery always takes us down a dangerous path that ends in ruin. It leads us to a place we hope is an ocean of happiness and satisfaction but actually is a cesspool of pain and sorrow. The heart’s duplicity always separates us from God and prevents us from experiencing His remarkable, exciting plans for us.

Why does the heart deceive us? Why does it make such herculean efforts to lead us astray? Because of its nature. Contrary to popular public opinion, mankind is not intrinsically good with just a few moral wrinkles to iron out. Remember, our hearts are desperately wicked. The heart insists on ruling our lives and refuses to yield to God. However, it happily allows us to act religiously and play church as long as we do not surrender our entire lives to God. As long as we allow the heart to remain in control of key decisions and to pursue cherished sins, it has no problem with us pretending Jesus is Lord and calling ourselves Christian.

So what are the most common arguments the heart uses to deceive us into justifying sin and allowing it to flourish? Here are four to consider.

1] God is leading me to sin. I call this the Christianization of sinful choices and sinful conduct. Basically, we live in whatever manner we want and convince ourselves it is the path God wants for us. We don’t seek His guidance, the counsel of godly friends, or the Bible for direction. What motivates us is simply our own desires. We determine what is best for us and make our decisions accordingly. We practice behaviors that produce pleasure and satisfy lusts. All the while we insist God is leading us to sin.

Perhaps an example will crystalize the point. Many years ago a friend informed me he had decided to divorce his wife. He explained that he had met another woman and they had fallen in love. He believed with certainty that God wanted him to marry the other woman. Therefore, to remain faithful to God and obey Him my friend had to divorce his wife. He had deceived himself so badly he actually believed God was leading him to sin.

Deep down my friend knew divorce was wrong. He also knew it was wrong to get involved with another woman. However, as an active and respected member of the church he faced a conundrum. How could he pursue his lust without losing his reputation in the church? He arrived at a solution many of us use in our lives. He declared it was God’s will. God was leading him to divorce one woman and marry another. Don’t blame him, my friend insisted, he was only doing God’s will.

Of course, God never calls people to sin. He abhors sin. Whenever we use ‘God’s will’ as a means to justify sin, we play a dangerous game. Not only does the sin separate us from God, but the justification blasphemes the Holy Spirit by suggesting He told us to sin.

2] Nobody is perfect. It is true. All have sinned and fall short of the glory of God. In fact, the Bible tells us that even our most righteous deeds are as filthy rags before God. But that reality doesn’t mean we ought to accept sin in our lives. We should not justify disobedience to God by declaring we are wired to sin. ‘That’s just the way God made me’ is not an appropriate response for explaining our inclination to sin. God calls us to lives of holiness that honor Him.

A recent encounter highlights the danger of adopting a ‘nobody is perfect’ philosophy to dismiss the pursuit of godliness in our lives. While sharing the gospel in a rough part of town recently I met an intoxicated pimp. I explained to him I was out praying for people and sharing the good news of God’s love. On hearing this he replied he was a Christian as well.

Surprised by the remark I asked him what that meant. He informed me that he loved God and regularly evangelized the call girls working for him. As for his immoral business and propensity for alcohol, well he couldn’t (or wouldn’t) change those things. Holiness was a bridge too far. Since perfection was unattainable he was free to pursue sin whenever he wanted.

Most would agree such a blatant abuse of God’s grace is categorically wrong. Yet I wonder how many of us practice a similar approach to faith but in a less dramatic manner? Do we make allowances for sin in our lives because “nobody is perfect?” Do we overlook selfishness, greed, and anger in our hearts with the same indifference as the inebriated pimp?

3] That’s legalism. A favorite retort for rationalizing sins of omission, the legalism argument is compelling because it prevails in so many churches. And it is dangerous. Legalism produces religious zombies who go through the motions of faith without having a real, dynamic relationship with Christ.

That said, we frequently ascribe to legalism behaviors we admire and embrace in a secular context such as discipline, diligence, and determination. Too often we defend spiritual laziness, inconsistency, and indifference with a nod to legalism. Instead of exercising ourselves in the faith and pursuing spiritual maturity with persistence we accept spiritual sloth as an acceptable alternative to avoid the pitfalls accompanying legalism.

Countless Christians rarely read the Bible, invest little time in prayer, and have never discipled anyone. Many resist allocating time to worship God daily, ignore opportunities to be generous, and seldom memorize Scripture. Few dismiss the value of these actions. In fact, most agree these undertakings draw us closer to God and strengthen our faith. But we fail to do them because misplaced priorities, worldly distractions, and unsound doctrine have left our faith in a state of ennui.

To reconcile this disparity between God’s expectations and our reality, we trumpet the danger of legalism. Pursuing spiritual disciplines like prayer, fasting, and Scripture memory is wrong, we declare, unless we do so with unbridled enthusiasm. And since we lack the requisite enthusiasm we must avoid the actions altogether. In doing so we parade ourselves as paragons of spiritual virtue when in fact we are spiritually stagnant. We ought to pursue these manifestations of faith with the same rigor and resolve we do our careers and our passions, even if at times it is a forced effort.

4] God wants me happy. This is a frequently employed rationale when we want to act selfishly. Do I choose the career with lots of worldly perks or a vocation that honors God? Do I spend a princely sum upgrading my perfectly functional kitchen or donate the funds to a ministry that cares for Christian refuges? Do I use my vacation time to relax on a beach or spend a portion of it serving victims of a recent natural disaster? Do I invest my annual bonus on a new toy for my enjoyment or helping destitute believers in third-world villages struggling to survive?

Instead of adopting the sacrificial model Jesus taught and lived, we often choose the option that gratifies. To avoid any guilt or angst over the decision we contend that God wants His people happy, satisfied, and comfortable. We ignore any biblical evidence to the contrary and in doing so reveal the truth of Jeremiah’s observation that “the heart is deceitful above all things and desperately wicked.”

I encourage you to examine your life and see if any of these deceitful justifications of sin influence your decisions, your behavior, or your worldview. If so, ask God to remove them from your heart and prevent them from deceiving you any longer. Instead ask Him to allow His Word to rule your choices and conduct. If you do, your life will never be the same.