Just for emphasis, I never 'enjoyed' spirits like I have for last 3 to 4 months. I am learning (and tasting) everything.

My question is this:

Say you have a guest call. They come over to your house to visit. With them they bring a bottle of (spirit)...or (beers).

Is it customary to serve that immediately? The reason I ask is because when I was growning up, and my parents would have company, they would bring liquor. However, all that liquor is still in my parents cabinets. Because.....they really don't drink. But is it a custom to serve it? What is the proper ettiquete regarding this matter?