Romans 6:16

Do you not know that if you present yourselves to anyone as obedient slaves, you are slaves of the one whom you obey, either of sin, which leads to death, or of obedience, which leads to righteousness? 

Romans 6:16 (ESV)

When we think of the word slave, we so often dismiss it as a derogatory term used to describe a weak person who is at the liberty of someone stronger or more powerful. This could be because they were bought, traded, or captured. We wouldn't be quick to say this kind of life is a blessing. So why are we likened to slaves so many times in the bible? I believe if we have a solid understanding of the answer to this question, we will have an easier time applying Romans 6:16 to our lives today.
The Greek term used in this verse to describe the word slave is "doulos." The important thing to note is that the word doulos actually has many meanings within the Greek language. Not only is it used to describe "slave," it also used to describe "servant" and "bondservant." A bondservant is someone who was freed by their master but has chosen to remain at their service anyway. This is how we could be described in relation to Christ. We have been freed from sin by our Savior but we have chosen to love and serve Him in response to the sacrifice He made for us.
This being said, we can remain in the bondage of our sin, or we can choose to be a bondservant of our Lord, Jesus. One leads to death, while the other leads to righteousness. We should make it clear to the world who our true Master is. We cannot say He is who we follow but continue in our habitual sin. As Matthew 6:24 explains, we cannot serve two masters.