A Jew is born in the covenant our forefathers made with G-d. We were given the Torah, and that’s how we should live. ‘Jew’ is our identity. The Torah is our lifestyle. There is nothing, and no one, that can change this.
Another Jewish blogger wrote this but it struck me as a good example of how Judaism is a product of its time. Afterall, why am I bound to serve a god just bc my great, great, great… grandparents agreed to? It reeks of the slave-mentality, back when people could be owned along with their offspring. Today - to me at least - this idea seems rather backward. It would be like punishing children for the sins of their (great… grand-) parents. Doesn’t make sense - at least to the modern mind.
As for no-one being able to change it. Well, again, I’m an advocate of free choice. I think an individual can define her own identity, her own lifestyle, and once done there’s nothing and no-one that can stop her.