1. Christianity (and its branched cults) is literally one of the only religions that claim that you are granted freedom once you are saved.
2. That's a strawman fallacy; Christianity doesn't grant you free will–you already have that. A Christian is freed from the enslavement sin had on him, for he then receives the better option, which is becoming a slave of God (and no, you can't not be a slave, you are either a slave to sin or to God, for this is a different kind of slavery).