I'd say because the bible says we shall think about holy things and pure things now if I imagine having sex with a person without being married to her then this isn't allowed or at least this is how christians tell it. If you're married you can fantasize about the wife but if you're not married you must not think about anything.
This assumes that thinking about sex is dirty and flows from a very puritan way of thinking. Can you back this perspective from the Bible, and can it be debunked from the Bible?
And in the bible there are also verses which speak about the lusts of the eyes or making a covenant with your eyes. These things also seem like you mustn't look at things which tempt you because this is how you get those thoughts in the first place.
Yet we are told that being tempted is not a sin.
If I had never seen any sexual acts then I could not even imagine these things and then I also could not think such things. You only think about such things when you've seen them before.
And yet if you happened to stumble across them, you wouldn't know they were bad. Or, if you didn't know what a temptation would look like you also wouldn't know you're being tempted.
And what about inappropriate content according to your logic? Do you think watching inappropriate content is okay as long as you don't "want to do something about it."
inappropriate content
always involves wanting to do something about it and you express this desire by viewing images that uncover another's nudity at best- which in the OT is condemned- and at worst treat other human beings as objects with which you pleasure yourself rather than people created in the image of God.
I hope you're not saying that because inappropriate content is totally addictive and dangerous.
Incorrect. inappropriate content
can be addictive and totally dangerous. An asexual person wouldn't find inappropriate content addictive, and a heterosexual wouldn't find homosexual inappropriate content addictive, for example. That's not to say it isn't dangerous, that's to say you're making a generalization that doesn't hold true in all cases.
Nobody can tell me that it's not dangerous I have experienced it first hand. Those images and sounds are totally hard to get rid of once you've been exposed to them.
Hard but not impossible. A bit of self control goes a long way. Thinking about how you shouldn't think about something never works. If I say, don't think about the computer in front of you, your first reaction is to think about the computer. However, if I tell you to think about Joshua 1:9, your first reaction is to go look up that verse if you don't know it and think about what it means and why I asked you to think about it and any thoughts about the sexy girl down the street aren't even going to cross your mind. Romans 12:1-2, by the way, is the basis for this simple principle.
That even our thoughts matter to God becomes clear from Jesus talking about hating somebody being like murder in your heart or lusting after a woman being adultery in the heart. The thoughts do matter and not just what you do.
If hate is to murder as lust is to adultery, then the thoughts, by your reasoning, must affect your behavior and emotions towards other people. Does thinking about sex always have this outcome?
I think you agree with me on this one right?
I think I'll hold off on answering that. My opinion is that you should research this for yourself, and you can't do that if I just tell you what I think the right answer is.