3 year old does a lot of “testing” boundaries

My 3 1/2 year old does a lot of defiant questioning or 'testing'. Today he was very nonchalant at the table saying "I believe in Satan mom and I listen to him." Or he has these cousins who are a little bit naughty and we've talked about their behaviors and that we don't always do what other people do or say. However, he likes to say that he listens to them and does what they do and say in a very teasing and nonchalant way. Or he'll say things like "I don't believe in God, I don't think he's real". Or when he's broken a family rule like hitting his baby sister he'll say something like "she likes when I do that", in a teasing manner and he'll always laugh about these things like he's the class clown or something.
I try not to have a big reaction because I know he's wanting attention but if he earns a negative consequence he smiles about it and laughs as if he's won. He happily does the chore as if he likes getting in trouble for stuff like that and is so pleased with himself, so I don't honestly think doing an extra chore for that is even helpful? When we talk about it he just laughs and laughs and doesn't listen or care about what we're discussing.