Most folks don't think of being a slave when presented with the American big-box church gospel.
Mostly, you get a self-help version of "Law Light" -- something along the lines of "Choose Jesus, he's the very best life program out there!" And then you're handed a set of do's and don'ts and told to get on after it, with as much enthusiasm as you can muster. Pay no mind to the steady line of people falling out the back door.
What the Apostle Paul calls us to is radically different. His gospel encourages belief in the face of complete un-believability.
God has promised to completely forgive all debit: past, present, and future. Every sin causes a debit before God, and we rack it up each day. So completely has He forgiven us in Christ we can hardly believe it; even when we knowingly, with forethought, our eyes wide open for the umpteenth time...FORGIVEN! Exonerated, debit wiped clean. Unbelievable.
Wait -- what's the catch? Well, there is no catch, and that's the problem -- we don't live in a world like that -- but thankfully neither does our Father who is in heaven.
In Romans chapter 6, verses 16-19, Paul explains it this way: You and I were born into a life of slavery. We are born slaves to sin or debit. When we are in Christ, we are still slaves, but to a different master...still slaves, and as far as I know, being a slave is never an easy life.
You were once a slave to death. You reaped pain, and struggle, and racked up more and more and more debit you could not pay. In Christ, you are a slave to righteousness. In believing what God has said about you, you can now present yourself to Him as a slave to right living. You still have pain and struggle, but no more debit of sin. We present ourselves daily to God as good, or as bad, but always as slaves to the work of crafting our lives so they may please Him.
So many of our brothers and sisters in Christ tremble, fearful of a master who can no longer touch them, fearing a debit that does not exist, a debit that has been paid eternally and in full.
We should first and foremost ask God to show us His great and precious promises just as they are in the Bible. Then, through prayer and purposeful action, present yourself to God as a slave to right living. And when you fail, no matter how badly or frequently, run to God and ask for his aid to understand why you have failed. God is not like our earthly masters. He won't fly off the handle.
He paid the price so you can come to Him in love and peace for healing. So come to Him in love and peace! Come to Him every day, if necessary, over and over again.
It will prove something amazing to you: you really do believe His promise.