"Before" vs. "in front of"

Especially in speeches I often hear a sentence like

I stand here before you...

However during my English classes in school (I'm German) we were told that before should only be used if you're referring to the passage of time (before we arrived at the party we left our home). When referring to a location in front of should be the choice of words (Peter is standing in front of me, so I'm standing behind him).

So, what's the answer to my confusion?

What you were taught is the usual way, so it's a case of being taught a heuristic rule which is 99% correct but doesn't actually apply to all cases. This is a more formal usage of "before", but there are lots of other examples of "before" for places and locations, e.g. "Two Years Before the Mast".

The New Oxford American Dictionary reports the following definition:

before |bəˈfɔ(ə)r| |biˈfɔ(ə)r|
preposition, conjunction, & adverb
1. during the period of time preceding (a particular event, date, or time): [as prep.] she had to rest before dinner | the day before yesterday | before the war | [as conj.] they lived rough for four days before they were arrested | it wasn't long before I had my first bite | [as adv.] his playing days had ended six years before | it's never happened to me before.
2. in front of: [as prep.] Matilda stood before her, panting | the patterns swam before her eyes | [as adv.] archaic trotting through the city with guards running before and behind.
• [ prep.] in front of and required to answer to (a court of law, tribunal, or other authority): he could be taken before a magistrate for punishment | a fall in the number of cases brought before the courts.
3. in preference to; with a higher priority than: [as prep.] a woman who placed duty before all else | [as conj.] they would die before they would cooperate with each other.

As you see, there are many examples where before doesn't have a temporal meaning.

"I stand here, before you now, truthfully unafraid. Why? Because I believe something you do not? No, I stand here without fear because I remember ..."

Morpheus