Personally, (I have no clue where the church falls on this) I believe that it has a lot to do with the reasons you are pirating the game. I have pirated several explicitly for the purpose of testing them to see if they are worth buying. Since very few developers put out demos now, this is about the only way to make sure I’m not wasting my money (reviews are good and all, but they are ultimately opinion, the only way to know for sure is to try it). If I do like a game, I will almost always buy it as soon as I am able. Along similar lines, I’d imagine that if you got it from a friend so you could play it together that’s not all bad, though I would suggest you purchase the game if you are able, because it is 1) more stable, 2) safer, and 3) more moral. (that said, I’ve played a few games at lan parties where I genuinely could not get the game any more, in those instances I think it’s fine because you’re no longer even capable of purchasing it).
Of course, if you are downloading them expressly to avoid paying for them, then you are definitely at fault; you’re also damaging the gaming industry and contributing to the annoying developers arms race to prevent piracy (which never works and only annoys the people who buy the game legitimately).
As for cracks, be careful with them. Some people use them as a way to get viruses on your machine. I see nothing wrong with using things like no-cd cracks because it just makes it easier to play your rightfully owned games; especially with newer games that are requiring an internet connection to play, period, like Diablo III. As soon as I can, I’ll be getting a crack to stop that little annoyance so I can always enjoy the game I paid for… or well, got as a birthday present.
As a small side note, if you are doing this because you get bored with your games and want something new to play, I would suggest you look into the myriad of free / cheap indie games out there. Minecraft has provided me with hundreds of hours of fun, and it’s only $20. No matter your preferred genre, there is someone out there who has create a free game in it. You should check out
pixelprospector.com, he keeps a catalouge of free indie games that you can play, sorted by genre. ( I highly suggest spelunky, it is frustratingly difficult, but incredibly, incredibly fun)