Calvin's Train of Thought

Dealing with Sin - April 18, 2022

The Text

Matthew 5:27-30 (NIV 2011) “You have heard that it was said, ‘You shall not commit adultery.’ But I tell you that anone who looks at a woman lustfully has already committed adultery with her in his heart.

If your right eye causes you to stumble, gouge it out and throw it away. It is better for you to lose one part of your body than for your whole body to be thrown into hell. And if your right hand causes you to stumble, cut it off and throw it away. It is better for you to lose one part of your body than for your whole body to go into hell.”


I once lived in an apartment building which had a cockroach infestation. About a month into my time there it was announced that there would be an extermination. So I went through and moved all of my furniture and bookshelves away from the walls, emptied out my cupboards and spent the hours in preparation for the extermination. But they only exterminated HALF of the building on the first day, and then HALF of the building on the second day.

As you might guess, it wasn’t long before the cockroaches were back, which led to more futile exterminations. The thing is, if they really wanted to get rid of those cockroaches, they would have needed to exterminate the whole building all at once, leaving the roaches no place to hide. But as it was, the half-measures they opted to use meant that the roaches could just move to a different part of the building on each day and so escape the exterminator’s chemicals.

Much like cockroaches, Sin - disobeying and rebelling against God - is something that we cannot take half-measures to deal with. While cockroaches are a gross nuissance that one could decide to just live with (yuck!), sin is like a deadly cancer that is NOT a mere nuissance. Our battle with Sin, unlike my battle with cockroaches, is a matter of life and death.

My Interpretation

Adultery Expanded

In the first part here, Jesus takes the Old Testament commandment against adultery - that is, sleeping with another man’s wife - and turns it up to 11. He explains that not only is the actual act of having an affair wrong, but even to look at another person in that sort of passionate and craven way, gazing for the purpose of fantasizing and feeding such sexual desires, is just as bad. As one author puts it, “The law forbade the act of adultery; Jesus forbids the desire…” (MacDonald, 1220).

Consideration for Why - Practical

Why is adultery - both the act and the thought - so problematic? I believe that part of it is that God created us to be in a heterosexual relationship composed of just one man and one woman for life. In the very beginning of the Bible it says: “for this reason a man shall leave his father and mother, and be joined to his wife; and they shall become one flesh” (Genesis 2:24)

to which Jesus adds: “So they are no longer two, but one flesh. What therefore God has joined together, let no man separate” (Matthew 19:6).

The way God has made us, we are not made to be in sexually intimate relationships with anyone other than our spouse. To choose to operate counter to God’s design in this regard is to - at best - destroy relationships, families, careers and more. Like adultery, lust - that passionate gaze across the room or in the minds eye that feeds sexual fantasy and desire - the way you look at or dwell upon that porn star on your computer screen or the well endowed person walking down the street - is destructive to our marriages, to our families and to our own selves.

From a practical and non-spiritual point of view, here are just a few of the issues that come along with pornography (and, by extension, lust):

  • It “decreases satisfaction with sex” in our marital relationships (Willmarth).
  • Among men, the way porn desensitizes us to dopamine can induce erectile disfunction (Willmarth).
  • This desensitization leads to porn not giving you the high it once did, leading both to more extreme pornography and potentially to real world affairs in order to achieve the same high (Willmarth).
  • It hurts your spouse, leaving them with feelings of betrayal (Willmarth).

Adultery, done both physically and in the mind, is incredibly damaging: it harms our relationships, it warps the way we look at other people, it wrecks our ability to be truely intimate… it rips families apart, destroys jobs and careers, and at times even leads to criminal prosecution when things have gone too far even for our sinful world to abide by.

So by all practical every day metrics, lust and adultery are pretty bad. But these “practical” every day metrics are just the tip of the iceberg: Lust and adultry are SPIRITUALLY destructive: They are what the Bible calls “Sin”, which I earlier defined as “disobedience to and rebellion against God”.

Consideration for Why - Spiritual: Sin

Sin drives a wedge between us and God. Sin is us saying to God “You may have made me and designed me, but I know better than you and am going to go my own way”. Sin is us fleeing from God, rebelling against God, spitting in God’s face. And our “reward” for Sin is death - to be eternally cast away from God’s presence and giving wholly and completely over to the Sin we loved so much. Sin, ultimately, is lethal.

Sin is such a big deal that God came to this earth, squeezing his vast and infinite self into a human body as the person of Jesus, that he might dwell among us living a perfect and sinless life and then ultimately pay the price required by our sin by dying a gruesome and horrible death in our place, rising back to life 3 days later in victory. What Jesus did was not trivial. It was costly. It is a big deal. Jesus died so that we might be free from Sin, no longer being a slave to it. Sin, is not cute, it is not something that we ought to tolerate. It is NOT “no big deal”. Sin is like cancer.

So if Sin – this living in disobedience to and rebellion against God - cost Jesus so much, and Sin is more deadly than the worst cancer, why do we act like it is something cute? Why do we as a culture celebrate and love sin? Why do many of us who believe in Jesus act as if it is no big deal, as if Jesus' work upon the cross gives us a license to sin with impunity? Suppose, if you are trapped on the roof of a burning sky-scraper and a helicopter comes to rescue you lowering down a ladder for you to grab onto, if you let go of the ladder and return to the burning building, does the fact that you held onto the helicopter’s rope ladder for a few moments now protect you from that building? No! Jesus saves us from our sins, because sin is so destructive and leads to eternal death. Just like the helicopter and the burning building, you cannot hold onto sin and Jesus at the same time: you have got to pick one! Now, I am not saying that we will not ever sin, or stumble, or the rest. Those of us saved by Jesus will still get tripped up by sin in this life. But that is quite different than giving ourselves over to sin and acting like Jesus gives us a license to sin.

Responding to Sin

Sin, such as the sin of lust and adultery in particular, are so terribly destrictive and pernicious, that Jesus calls us to do whatever it takes to address them. “If your right eye [snares you and causes you to sin]”, says Jesus, “tear it out and throw it from you: for it is better for you to lose one of the parts of your body, than for your whole body to be thrown into hell” (Matthew 5:29). Likewise, Jesus says “If your right hand [snares you and causes you to sin], cut it off and throw it from you: for it is better for you to lose one of the parts of your body, than for your whole body to go into hell” (Matthew 5:30).

This is serious stuff. It is not something to mess around with. I don’t think Jesus was literally calling us to gouge out our eyes if we look lustfully at another person and to cut off our hand if it similarly leads us into sin (since that generally does not actually deal with the root problem), but Jesus IS calling us to do whatever it takes to deal with sin, regardless of what it might cost us.

My Example

So what does this look like in practical terms?

Let me give you an example: I used to watch a lot of pornography. But eventually, Jesus got hold of me and made it clear to me, through passages in the Bible like the one we are looking at today, that it needed to stop - that I needed to take this seriously. So how was I supposed to deal with it?

Well, since internet pornography was where I particularly struggled, I tried accountability software like Covenant Eyes - a program you install on your computer and phone that keeps track of the websites that you visit and sends reports to another Christian you choose who will hold you accountable and call you out when… questionable… webites show up in your browser history. But, I am a computer technician by trade, so these programs cannot stop me - I know all sorts of ways to get around them. So considering Jesus’ words to cut off my hand if it causes me to sin, I knew I had to get rid of my internet access at home.

And with how much relies on internet these days, it is easy to say “oh, but I NEED the internet”. Yes, but you also “NEED” your right hand and your right eye, yet Jesus says we ought to gouge those out if they were somehow to be the root cause of sin. “Oh, but there is so much good to be gained from the internet! I can learn things! I can apply for jobs from the comfort of home! I can do all of these things!” To which Jesus replied in Matthew 16:26: “For what will it profit a man if he gains the whole world and forfeits his soul?" (NASB) What good is it if I gain all of the good stuff the internet has to offer and yet lose my soul to the ravenous appetite of Sin?

So I got rid of my home internet. Then, I got rid of my personal cell phone connection. When I wanted to go online, I had to take my old laptop someplace public where the temptation to look at porn was non-existent (because that would be rather embarrassing to get caught doing that). When I go someplace that is going to have unmonitored internet access, I will often leave my laptop at home because I know it will be a source of temptation.

These days, work provides me with a cell phone that I can use for internet, and because I am accountable to my employer for its use it is not a temptation. But if I were to change jobs, so long as having home internet remains a source of temptation, I would have to live without it.

Sin is so deadly and destructive that I must do whatever it takes to stamp it out. If the internet is the source of much of that sin, then I don’t want it - no matter how vital we think it is for our survival! If having gadgets is the source of that sin, then I want to go back to paper and pencil. Whatever it takes, I don’t want any part with sin!


So what are you going to do about the sin in your life? I know for many - if not most - of you, sexual sin and pornography are pervasive. Some of you sleep around, some of you engage in same sex activities, some of you watch pornography, some of you look lustfully at others and fantasize. What are you going to do about it? What is God asking you to give up - to cut off?

Sin, such as sexual sin, is so deadly that we must stop at nothing to eradicate it from our lives.


Lord Jesus, Help us to see just how truly bad sin is. Help us to not see it as a fun pass-time like the world does, but help us to see it like you see it. By your power, empower us and grant us the courage to do whatever it takes to cast that sin out of our lives. Help us to turn our backs on the sin we once loved and to turn our eyes to you. In your most precious and holy name. Amen

Works Cited

Marsh, N. M. (2016). Adultery in the Bible. In J. D. Barry, D. Bomar, D. R. Brown, R. Klippenstein, D. Mangum, C. Sinclair Wolcott, … W. Widder (Eds.), The Lexham Bible Dictionary. Bellingham, WA: Lexham Press.

Vine, W. E., Unger, M. F., & White, W., Jr. (1996). Vine’s Complete Expository Dictionary of Old and New Testament Words (Vol. 2, p. 136). Nashville, TN: T. Nelson.

Willmarth, Abby. “Porn in Marriage: Its Harmful Effects on Relationships (and How to Heal).” Covenant Eyes, 16 June 2020,