To commit an act of sin can lead to yielding ourselves to that master. We will look at that in a moment but first lets look at the rest of this verse. You would think he would. But no for that would teach salvation by works. The word translated justify is from the same root word as this word righteousness but they are 2 different words.
Justification means to declare righteousness sanctification means to make righteous.
Here in chapter 6 he is speaking about our sanctification as the inevitable result of justification. Keeping that in mind lets look at the next verse to see if we can answer the statement about yielding ourselves to sin. 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 we a simple statement that shows that the child of God is no longer a slave of sin. The imperfect tense speaks of continuous action in the past.