I'm constantly shocked (but I guess shouldn't be) at how much Christianity tries to look like the world, even including those things that do not glorify God.
Please give me a few examples of how 'Christianity' is trying to look like the world, especially in ways that do not glorify God. As I see it, Christianity, being a belief system, cannot try to look like anything, seeing as it is an idea, not a living person. If you're talking about Christians looking like the world, that's nothing new. There are subjects in which that actually matters and shows that these Christians aren't in the right, and there are subjects that just don't matter. This is one of those that just doesn't matter. It's dressing up as a favorite character and getting candy and putting up spooky decorations. Some people go to 'haunted' houses, parties, and themed amusement parks (ValleyScare, anyone?), but that's not really my thing.
And I see NOTHING wrong with saying 'no Christian should do these things'. There are plenty of things in Scripture that were given to His people as a whole, not just individuals.
Then please explain, using Scripture, why Halloween is a holiday that no Christian should participate in. Also, do this in a way that is logically sound, historically accurate, and utilizes references to show that what you claim is historical fact and then demonstrate that how Halloween is currently celebrated either is directly tied to something that would make people sin by celebrating it, or is inherently sinful.
Why do we make Christianity so relative and subjective?
Because it IS relative and subjective. Romans 12, each have different gifts according to the faith given them. Gifts of the Spirit, 1 Corinthians 12. As was already brought up, Romans 14 and that which one feels comfortable doing and another they don't. I don't feel comfortable eating something I killed or killing things, so I don't hunt. Others have no problem with it, and that's fine. Like it or not, everyone has different preferences, different understandings of the Bible, and different ways of thinking.
He wants His people as a whole to be set-apart to Him and His ways. And I'm not afraid to say so.
What you are or are not afraid of isn't the subject of this discussion. Nowhere does it say in Scripture that we shouldn't practice a holiday just because it's practiced by the majority of a nation. This isn't really an issue in which we need to be set apart. Demons aren't going to come and get me for clipping a lightsaber to my belt and throwing on a Jedi robe, nor will the world think I'm not a Christian for doing so. Ironically, the only people that would have a problem with it are other Christians who think Halloween is evil.