Romans 6:17-23
Rom 6:17 (KJV)
But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.

Here the apostle Paul is telling us that the true believers were once servants of sin. That word “servant” is better understood as “slave.” Notice that it says we “were” and that we are not now.
(1 Cor 6:10-11 KJV) Nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God. {11} And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God. Notice in these two verses from 1 Corinthians, Paul states the same things that the true believers “were” vile sinners but through God’s salvation, they are now sanctified and justified in the Lord Jesus Christ. The fact that we are now saved, means that we now have the strength to obey the form of doctrine which was delivered unto the brethren. Those who are unsaved do not have the ability to obey the doctrines of Scripture simply because their hearts have not been regenerated. Only those who have been saved have the ability to obey the true gospel.

Rom 6:18 (KJV)
Being then made free from sin, ye became the servants of righteousness.

Since we were once slaves to sin, when God saved us, He made us free from sin and its bondage. When God freed us from the bondage of sin, we were not made free agents to do as we wish. God made us servants of righteousness through the indwelling of the Holy Spirit. There was a time in our life that we served sin but now through regeneration, we now serve righteousness. What must be kept in mind here is that because our souls have been freed from sin, we still have a body which lusts after sin and therefore the true believer still struggles with sin in their life. However, the situation has changed, when we were unsaved, we served sin without any hesitation but now we have the ability to resist sin and to live righteously before God.

Rom 6:19 (KJV)
I speak after the manner of men because of the infirmity of your flesh: for as ye have yielded your members servants to uncleanness and to iniquity unto iniquity; even so now yield your members servants to righteousness unto holiness.

Paul explains that he was using the analogy of being a slave to sin because he knows that the infirmity (weakness) of the flesh can still get us into trouble. Paul states that as unbelievers we lived from sin to sin, that is because we were servants of sin. When a person is a servant or slave, their entire life is dedicated to the one they are serving. When a person is an unbeliever, their entire life is spent in servitude to sin. Now that we have become saved, we are, in like manner of slavery to sin, we are to become slaves to righteousness and to serve righteousness as strongly as we served sin. We used our body and our earthly goods to serve sin so now we use those very same things to serve righteousness.

Rom 6:20 (KJV)
For when ye were the servants of sin, ye were free from righteousness.

This short verse gives a powerful principle. That principle is that everybody is a slave to something. Before we became saved, we were slaves of sin and were free from righteousness in our life. In other words, we had no problem in engaging in any sinful activities because our minds were still unregenerate and darkened in sin. Righteousness does not dwell in the unregenerate mind. Not only did we have no righteousness, we did not desire to have any since it would interfere with our sinful activities.

Rom 6:21 (KJV)
What fruit had ye then in those things whereof ye are now ashamed? for the end of those things is death.

When we look back at what we did before we became saved, what did those things really profit us? Did they bear any fruit that would be beneficial for the rest of our lives? Did they bear any fruit which would be beneficial in the lives of those we knew? When we look back through the eyes of salvation, we realize that the things which we did had no fruit except to send us to an eternal damnation. Our life of sin yielded no good things which could benefit us. Those things which we did, we hope they never come to light since they could be embarrassing to us.

Rom 6:22 (KJV)
But now being made free from sin, and become servants to God, ye have your fruit unto holiness, and the end everlasting life.

In contrast to living the unregenerate life with its fruits that ends up in eternal damnation, Paul now states that because God freed us from sin, and that we are serving Him, the fruit that we now produce will end in everlasting life and not everlasting damnation. There is the great difference between being the servant of sin and the servant of righteousness. God made us holy and with that our works are holy.

Rom 6:23 (KJV)
For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.

As with everything evil in this world, there are consequences. Here God uses the word “wages” to state that a sinful life will receive compensation and that compensation is that the wages of living a sinful life is eternal death. He then contrasts that eternal death with the great gift of salvation which God gives to His Elect through the Lord Jesus Christ.