As a young 15-year-old, the common problems within my age demographic is present, being lust and temptations of the flesh. Most of my classmates and fellow male friends tend to give in to this; however, being a Christian I know the consequences of doing so. But again, as one who is weak and young, I am very vulnerable to these things. I have long since overcome the desire to masturbate and to watch pornography, but every now and again I find myself having dastardly evil and lustful thoughts, and I find myself checking out some pornography again, though I resist the urge to masturbate, I still know the fact that I have lusted. No justifying that.
And evil pop-up thoughts just come out of nowhere — very evil and blasphemous thoughts. I don’t think about these on my own. It just appears in my head. Though it is most apparent when I am in a weakened state, like when I am stressed or tired. This disturbs me, for I am very much against evilness and sin. I can’t help but feel guilty for having these thoughts, for I feel as if I have failed to make a strong foundation within my mind, and I can’t help but feel guilty of having such dastardly thoughts, even if they weren’t mine. Like I said these are intrusive and unwanted thoughts.
“No temptation has overtaken you but such as is common to man; and God is faithful, who will not allow you to be tempted beyond what you are able, but with the temptation will provide the way of escape also, so that you will be able to endure it” (I Corinthians 10:13).
You are correct that what you are dealing with is common for your age. But this also means that there are solutions as well.
Since you are a male, you have a physical need to ejaculate once in a while. It appears that wet dreams handle your need for relief most of the time. The problem that arises is that as your seminal vesicles get full, your sexual drive gets stronger. There are times that you haven’t had a wet dream in recent days and your sexual drive gets really strong. It is at those times when you are most vulnerable to engage in lust or look at pornography. You need to recognize when you approaching that point and find things to do that don’t involve your phone or computer until you have another ejaculation.
There is one thing I need to point out. While you stated that you’ve overcome your desire to look at pornography, you still do so — you just do so infrequently. Thinking that you’ve conquered sin is a danger. “Therefore let him who thinks he stands take heed that he does not fall” (I Corinthians 10:12). The honest view is that you still struggle with pornography and you need to remain guarded against it. Using Internet filtering software can help during weak moments.
A person might convince himself that having a bad thought is just as bad as actually doing something sinful. Actually, this is a warping of Jesus’ statement, “But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart” (Matthew 5:28). Jesus didn’t say if you had a passing thought about a woman (a temptation) that it was the same as committing adultery. He said that if a person looks to lust for a woman has committed adultery in his heart. In other words, when a person contemplates the idea, strongly desires it as something they want to do, and only lacks the opportunity to do it, then it is little different from actually doing the sin. That is a key difference. When we are faced with a thought about sin and our gut reaction is to reject the thought, then that is overcoming temptation!
A variation on this is that a person might convince himself that having a bad thought will lead to the actual action. They discount the fact that they don’t like the thought. They don’t realize that their hatred of the sin will produce the opposite effect — they will be less likely to commit such a sin. “I will set nothing wicked before my eyes; I hate the work of those who fall away; it shall not cling to me. A perverse heart shall depart from me; I will not know wickedness” (Psalm 103:3-4).
We can’t avoid being tempted and some of those temptations will involve the things we think about. Being tempted is not a sin, it is Satan’s attempt to get us to sin. Resisting temptation is what we are supposed to be doing.