So I find it to be a law that when I want to do right, evil lies close at hand. (ESV)
Paul has spent a lot of time explaining the doctrine of grace and how that relates to the Old Testament Law. We have discovered that the Law of God is perfect. It is a standard of God's perfect holiness that none of us are able to attain to. Jesus Christ comes into the picture and lives a perfect life for us, fulfilling God's law flawlessly. Our new way of righteousness is through Christ, not the Law.
Now, Paul is talking again about the law. This law is not the same as the Old Testament Law. He is using the word law as a principle that is consistent in our lives. Perhaps you have heard of "Murphy's Law." Murphy's Law says, "Anything that can go wrong, will go wrong." This "law" is establishing that some people seem to always have things go wrong. It doesn't mean they have to.
So, Paul introduces this principle that when he wants to do right, evil lies close at hand. Christian, please hear what the Apostle Paul is saying to you. When you are focused on pleasing the Lord, be assured of this principle that Paul describes. Evil is close at hand. The enemy is not going to applaud your decision to act in righteousness. He will be actively against you.
We ought not be surprised when the enemy comes rushing in to tempt us to do wrong. It is usually right at the same time that we are attempting to do what is right. This law is at work all the time. We need to stay strong, knowing that "he who is in you is greater than he who is in the world" (1 John 4:4).
To be forewarned is to be forearmed. Be aware of this law that is at work in your life. When you desire to do what is right the enemy will be right there to distract you. Look to the Lord to help you through.