What does it mean to "bless" something?

[Brakeman]

To bless is to wish well or from God is to protect, and prosper.

Calling something sacred, if one is not an Old Testament Jew, is borderline idolatry. In Christianity the unclean/clean classifications things had in OT times is at an end.

Biblically, the only reason to anoint someone with oil as a Christian is if they were sick, as in James 5. The oil kept them hydrated, to soothed and was a traditional way to offer comfort.

OK, thanks, you've touched upon the subjects, but when the Lord's prayer tells us to bless food, we are not wishing the food well, it's dead. What does it mean in that context?

You say that basically only an old testament jew can deem something sacred, but why? When only souls really matter, why was there ever reverence for objects?

What does un-clean / clean really mean to a christian? Is it just for the jews?

Lastly, though I contend that pouring oil on one's head doesn't help hydration in any way, anointing was obviously very big in the bible. Even the word Messiah means "anointed one." What does it do apart from what does it signify? Why would god come up with such a strange ritual?

Thanks for your answers, I'm truly interested in your POV.