Jesus was very clear on the issue of sexual lust and fantasies:
27 “You have heard that it was said, ‘You shall not commit adultery’; 28 but I say to you that everyone who looks at a woman with lust for her has already committed adultery with her in his heart. (5:27-28)
Jesus is getting to the root of adultery in the heart and mind – lust in the heart.
29 If your right eye makes you stumble, 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. 30 If your right hand makes you stumble, 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. (5:29-30)
The point is not to literally physically cut off your hand or gouge out your eye. The point is to decisively and radically (getting to the root) quit doing things that will make you stumble or lead you to stumbling. (failing and sinning) The violence of the verse is demonstrating that the quitting must be decisive and hard and will be painful. It is painful to go on a real diet, for those who struggle with gluttony. It is painful to go into physical exercise for training for the olympics or some kind of sports activity. “No pain, no gain” has a lot of truth to it. Some ancient Christians misinterpreted the verses and took them literally, and they later confessed that the lust and visions of the beautiful women were still in their minds. Lust starts in the mind and heart. The point of verse 27-28 is for those self-righteous people who have not committed real physical adultery who think they will be ok and they are good because they have not sinned; . . . well, think again! Sexual fantasies and lust make us just as guilty for hell. It is the second lingering look and playing with the thoughts in your mind that are sinful. If you are converted / born again/ a true Christian, you must fight lust and pornography! The point of verses 29-30 is to take hard action against anything (thought, action, practice, environment) that will lead you down that path. We have to cut off friends and activities that will tempt us to go down that path. Having a computer filter / blocker is good and an accountability person who can see the web-sites you visit and they will get flagged when you do. (Like Covenant Eyes) Too much Cable TV wandering or YouTube wandering can expose you to scenes that are not necessarily pornographic, but are tititaling enough to get you started on that path that you don’t want to go. Pornography kills relationships and goes against what God has designed sex for. Sex is a beautiful thing that God thought of and created (Genesis 2:18-25) and only for marriage between one man and one woman. (Song of Solomon; Proverbs 5:15-23; chapter 7; 1 Corinthians chapter 7.
Jesus also taught that marriage is only for one man and one woman. Matthew 19:4-6 and Mark 10:1-9. Jesus alludes back to Genesis 1:1, 1:26-28; 2:18-14; 5:2 and quotes Genesis 2:24 – “male and female”, “the beginning of creation”, “the creator”, “the two shall become one flesh”. Beautiful! This proves that there is no such thing as “same sex marriage” and don’t let anyone tell you that “Jesus never spoke about homosexuality as a sin”. Jesus, by His clear affirmation of Genesis 1-2 and the Creator’s design for marriage, was very clearly teaching that homosexuality is wrong.
Colossians 3:5 is another excellent verse on this: “put to death” those things (lust, passion, evil desire) – I remember years ago a Bible teacher quoting a Bible scholar, John Eady: “let them be killed by lack of nutriment and lack of exercise”. The KJV says, “mortify”. That’s a graphic and effective way to describe the command. What does a mortician do? He handles dead things; treat your members on this earth as dead to sexual immorality, impurity, passion, evil desire, and greed. The NIV, ESV and other good versions say, “put to death”
“Therefore consider the members of your earthly body as dead to immorality (porneia / πορνεια – fornication, where we get “porn” from – it includes any kind of sexual sin outside of marriage, pre-marital sex. “trafficking with prostitutes”) impurity, passion, evil desire, and greed, which amounts to idolatry.” NASB
Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. Colossians 3:5 ESV
Another important passage is 1 Thessalonians 4:1-8. Meditate on those verses. Also, 1 Corinthians 6:12-20 – meditate on those also. Fortify your mind. Memorize verses and quote them out loud when temptation comes. (like what Jesus did in Matthew 4:1-12 and Luke 4:1-12) Get outside and go for a walk to get away from the TV or computer is they are tempting you or you are attacked by sudden thoughts of the “flaming missiles of the evil one” (Ephesians 6:10-20)
Desiring God (John Piper and other writers) and Tim Challies have A LOT of great resources for Christians to deal with sexual lust and pornography. A lot of the advise is to cultivate a heart of worship and desire for God that sees the beauty and enthrallment of God as a superior joy / pleasure than the fleeting pleasure of a 5 minute look and masturbation trip. It is not enough to confess your sins privately to God and then claim 1 John 1:9. Certainly the truth of 1 John 1:9 is great, awesome, and freeing! Believing it is actually seeing how your sin put Christ on the cross. We can forgive others, because Christ first forgave us at the cross. (Ephesians 4:32; Romans 3:24-26 – see the propitiation that Christ made as the turning away of God’s justice / wrath against your sin; that Christ absorbed the wrath of God for your sin. Meditate on that truth. We never stop meditating on that truth. You should confess it to God and weep over your sin in prayer, repentance, and sincerity. But that is not enough to fight the battle of lust in preparing for the next time that temptation comes. We need each other in the body of Christ, the church; we need accountability. (Hebrews 3:12-14; 12:15; James 5:13-16) There needs to be a friend and accountability partner than you can confide in, confess to, and someone who will keep you accountable. A close friend you can share your struggles with; someone who will not condemn you, but will be honest and straight with you, who cares about you. Preach the gospel to yourself also; learn the gospel application to sanctification, not just to justification / conversion. (see Jerry Bridges book, “The Discipline of Grace”)
If you are struggling with this sin, check out the many articles and videos and suggestions in these 2 websites:
John Piper also has an excellent chapter on fighting lust in his book, Future Grace. I recommend that book.
An excellent book is “Finally Free” by Heath Lambert