This week's Torah reading is Parshas Terumah, in the book of Shmos (Exodus). The Jews are told to make a Sanctuary within which to worship G-d. Very glorious and full of gold.
Finding the instructions about Temple-building pretty dry I didn't even want to read the commentaries. I closed the Bible.
And then I realized...this Parsha is a pretty big deal.
G-d doesn't need our gold or our sacrifices.
G-d, being G-d, doesn't need ANYTHING.
The purpose of all this is our well-being.
To give us peace, in a world full of people who can get pretty nasty and dictatorial. That we serve only Him and never them.
Similarly when we get dressed in the morning it's good to wear clothes that are as nice as we can.
Not because we're egotistical, but because we're creations of the One True G-d, and as such we need to show a certain amount of self-respect and not put ourselves down.