"For freedom Christ set us free; so stand firm and do not submit again to the yoke of slavery. For you were called for freedom, brothers and sisters. But do not use this freedom as an opportunity for the flesh; rather, serve one another through love." (Gal. 5:1, 13)
Freedom and service at their face seem some how opposed to each other. If we are in service, we submit our own will to the needs of others, which contradicts the idea of freedom, right? Not when the choice to serve is made willingly and out of love. Pope Benedict XVI put it better than I ever could in a weekly address (read here for the complete text):
Luke the Evangelist tells of how Jesus, 'When the days for his being taken up were fulfilled, resolutely determined to journey to Jerusalem.' (Lk 9:51). In the expression 'resolutely' we can glimpse the freedom of Christ. He knows, in fact, that in Jerusalem, death by the cross awaits him, but in obedience to the will of the Father he offers himself for love. It is in this, his obedience to the Father, that Jesus fulfills his own conscious choice motivated by love.
Who is more free than the One who is Omnipotent? But it was a freedom he didn't see as arbitrary or as one of dominion. It was one he viewed as service. In the process, he "restored" what freedom means, otherwise it would remain 'empty' opportunities of doing or not doing something. And so in the life of man, freedom brings with it a sense of love.