Before you look at the title and have me committed or ex-communicated, hear me out.
A few years ago, I posted my thoughts on a screen name, "IAmNotaSlavetoaGodWhoDoesn'tExist." My view has changed on it since then, as you can already tell. Christianity is slavery, in a sense.
It's not slavery as we know it from pre-Civil War, where humans were treated as property and forced to work their master's home with little or nothing in return. In Old Testament times, slavery was more of a servanthood. A man or woman would offer himself to a master to work so he or she could receive money to send to their family. In law like Leviticus, God commanded that these slaves be treated well, and offered freedom after a set amount of time.
Christians are these types of slaves to God. We offer ourselves to Him humbly, and are given love, mercy, grace, and everlasting life in return. It is fully our choice to come to Him, and we are duty bound to spread His word of hope and forgiveness across the world. That's what it means to be a slave to God, to follow His word and get so much in return, never being turned away when we fall short. Sure, we are disciplined when we fall short, but never more than we can handle, and it's because He loves us and wants the best for us. A slave driver of the other connotation has no love.
Do you see the difference, now? I hope this makes sense, and gives you a better view of our God.