For some reason some players get scared when faced with1.g4. There is no reason to fear this. True, if you waslk into the jaws of the beast, your head can get chopped off. But if you play sensibly there is no danger. Here are two examples of solid, principled play by Black. Control the center, develop sensibly, and exploit the weaknesses. If your kingside has no weaknesses, your opponent can't mount an effective attack.
The next example is similar.