Does the Offset really matter when buying a rim?!?

Im looking to buy some wheels for my vw golf 2000. The rim size is 5x100 and the offset is 43. Does it matter if i buy a different offset but the same 5x100 lug pattern? What if i buy a different offset than the one i need? What will happen and will it damage the car/suspension . What long term damages will occure? Or will it just work?!