Is lust sexual fantasies?

Last updated on August 27, 2020


I’m a 16-year-old Christian male with a few questions, but before I continue, I just want to say that I am a great believer in God and I hate to disappoint Him. I have been a Christian since I was very young as my mother had me christened as soon as possible after giving birth. I have always asked questions about my religion, but it isn’t until recently that I have become really paranoid about the things I do. It all started when I didn’t understand some of the words in the ten commandments and I started to research them. I then came upon the word ‘lust’ and I realized that this meant sexual thoughts. But then I came upon it again on a completely different Christian web site that lust was the desire to take something that belongs to your neighbor with intentions to steal. (Not sexual thoughts as they are a mere fantasy and can’t harm anyone unless you act upon them.)

Then I wondered about masturbation. I didn’t know if it was a sin or not as I’ve searched the Internet very deeply and everyone says that lust is sexual thoughts and everyone also says that fantasy isn’t lust. Lust is when someone wants something that is their neighbors and they have plans to actually take it from them. I’m so confused. But then something clicked in my mind, I prayed to God and I promised Him something, but I broke it. I gave in to the temptation. It was nothing very big, the promise I broke didn’t hurt anyone I love because it was all private to me. I only hurt myself (mentally) because I didn’t feel guilty for it, but I wanted to feel guilty. (The guilt came a bit later on.) Later I was praying to God for forgiveness, I actually cried. I know deep down that He has forgiven me because He promised and His Son died for all our sins. But I think ever since I wanted to feel that guilt because I didn’t feel guilty for what I did. It did come, but now I can’t get rid of it.

I feel like I’ve let God down still with the promise I broke. Is it the devil or his demons trying to make me feel guilty and trying to make me give up on God (which will never happen)? I also fear what will happen to me after death, but I still know that I have God’s forgiveness. I’m starting my education afresh in at least one week’s time and I don’t want to fail my studies just because I can’t forgive myself. I’ve tried so hard. Sometimes it worked, but then, later on, it comes back again. I feel depressed. Is it because I haven’t forgiven myself or is God punishing me for breaking a promise (even though it was private and didn’t hurt anyone)? Don’t get me wrong, if God wants me punished, I’ll always accept it because I know it’s what I deserve. I will always agree with God, that is a promise I haven’t broken. 

I would be happy if you would reply to this problem of mine. I could really use the help. Thank you.


I don’t want to add to your list of things to consider, but I must point out that christening is not what the Bible says is needed to become a Christian. This is a side topic to what you came asking, but I want you to get a Bible and read through all the passages mentioned in the following articles:

But let’s get to your actual questions.

You are circling around the definition of “lust.” Lust means a very strong desire, both in English and in the Greek from which it is translated. It can be used in a good sense, but that is rare. We almost always talk about lust in a bad sense. Thus, lust is usually a very strong desire for something that would break a law of God. The most common strong desire is sex, so lust is often connected in people’s minds to sexual desire, but it is not limited to sex.

To prove this, take a look at I John 2:16-17: “For all that is in the world — the lust of the flesh, the lust of the eyes, and the pride of life — is not of the Father but is of the world. And the world is passing away, and the lust of it; but he who does the will of God abides forever.” All sins are based on combinations of one or more lusts.

  • Lusts of the flesh are built on the natural desires of the body. That would include sex, but it can also include hunger or thirst.
  • Lusts of the eyes are built on our natural desire for beauty.
  • Pride of life is built on our natural desire to be liked and to think well of ourselves.

Satan uses those natural desires against us by putting us in situations where it appears to get what we want, we have to break a law of God. That is called temptation. When we strongly desire whatever we are being tempted with so that we will consider it even though we know it is wrong, then that becomes lust.

Read “What is Lust?” for more on this subject.

I get asked about masturbation so often, let me direct you to some prior answers. If you have additional questions, you can always write and ask.

You didn’t say what you promised, but I suspect that you promised something that could not be kept. For example, I could not properly promise not to sin. “If we say that we have no sin, we deceive ourselves, and the truth is not in us” (I John 1:8). Such impossible promises are common among young people because you don’t have experience in dealing with the world.

From this, you make another common mistake. You decide your status with God based on your feelings. “He who trusts in his own heart is a fool, but whoever walks wisely will be delivered” (Proverbs 28:26). You are not being fair to yourself because instead of letting God and His word decide whether you are right or wrong you are acting as judge and jury. In a sense, you are putting yourself in the place of God. It is God who forgives because your sins create a debt to God. You cannot really forgive yourself because you cannot truly owe a debt to yourself. Notice that there is no mention of feelings determining our relationship with God in the following: “Now by this we know that we know Him, if we keep His commandments. He who says, “I know Him,” and does not keep His commandments, is a liar, and the truth is not in him. But whoever keeps His word, truly the love of God is perfected in him. By this we know that we are in Him. He who says he abides in Him ought himself also to walk just as He walked” (1 John 2:3-6).