I'm not going to help my friend's move.
Why aren't you going to help your friend's move?
I don't feel like it.
Whether or not you feel like it, it is rude not to help your friends move when they are in need of help. If you don't help your friend's move it will be a lot more work for them and the process will take longer.
I don't think that's a valid reason to help him. I have a life outside of my friends.
If you didn't help him when he's in need probably that'll affect your friendship negatively. You need to keep your attitude aside if you want to maintain relationships with people.