When the angel came to Mary he made it very clear that our Savior's name would be Jesus, for He would save His people from their sins. We are saved by the only name given to accomplish that, JESUS. We live in the power of that name by accepting His grace which results in our freedom. We use our freedom to serve, because THAT'S HOW FREEDOM GROWS. It's not an external duty. It's an internal expression of faith following the lead of the Holy Spirit.