creating a law for themselves...

Romans 2:12-16

Observe:
The law is a key word in this passage, repeated 10 times. The idea of righteousness and judgement continue to be key. Paul is contrasting the judgement that those who don't have the law (the Gentiles) will receive to what those who do have the law (the Jews) will receive. Paul concludes that the law is not just what is written in the Bible but is the conscience and morality of humans.
A phrase that stands out is "my gospel" (v. 16). Paul identifies so closely to the good news of Jesus Christ that he makes it his own.

Interpret:
Paul is continuing his thought from v. 11 - God does not show favouritism. The proof is that he doesn't use the law to judge people who never had the law. That would mean that the Jews were his favourites since they were the ones that he revealed the law to.
The main argument of this passage picks up on what Paul said in 1:20 - humans are without excuse before God, even if they never had the law, because they can see the attributes of God in creation (chapter 1) and they have a conscience (chapter 2). Paul argues that because we have all done things that have gone against our conscience, we all stand guilty before God. For the Jews, the Law is the standard of holiness but for the Gentiles, the law of God is written in our conscience and our hearts. Even without knowledge of the law, there is knowledge of right and wrong.
This fits into this chapter specifically because it is all about the justice of God: God's judgement is based on the truth (v.2), on our deeds (v 6-11) and on the knowledge of God and his standard we have (v. 12-15).

Apply
This speaks to God's justice. He will do what is right and just in every circumstance. It also speaks of God's patience because, while he is revealing his wrath against wickedness in the present, he is waiting to pour out the full extent of his wrath until the day of judgement. The only reason he is delaying his judgement is to give more of us time to repent. This is incredibly kind and patient of God.
I need the Holy Spirit to make my conscience soft again. I've justified my sinfulness for so long that I've effectively shut off my conscience and silenced the voice of the Spirit in certain areas of my life. Since my conscience is one of the ways that God communicates to me, then I am desperate to open up that channel of communication again.