It is good to be a free thinker, but only if you do not go against the teachings of God or against God because you can go to hell for that. It would be consider a crime against God.
I think that all we have is the 'self'. We understand the world through our own perceptions. We can only change the world by thinking for ourselves, if people didn't have their own ideas, and only followed the people before/around them, things like slavery may never have been abolished etc etc.
No it is VERY wrong to be a free thinker, and you must pray and go to church to be a christian, wether you are a good person or not. I can still be myself and have my own beliefs when I go to church with my family. Fake it , and maybe you will even be a better christian than your parents will ever be.