What most western Christians fail to realize is that Jesus was a Rabbi, AND the Son of God, who came to keep the law because we could not. Therefore he was a teacher of the law. Jesus did not teach new testament theology. He was an old testament teacher, a teacher of the law.
However, once he did fulfill the law and died, and rose from the dead, the new testament was set into motion. Peter, John and especially, Paul were teachers of the Gospel. Paul was sent specifically to the gentiles. Did he teach them the law? No. He taught them the message of Grace.
So the problem that western believers have is that we try to mix the law and grace, and it doesn’t work. It is because we don’t realize that Jesus’ life was to first fulfill the law, SO WE WOULDN’T HAVE TO. So the only thing we need to “DO” is believe.
I spent the first 25 years or so of my Christian life trying to keep God’s law. The more I tried the worse my sin became. (Read Romans 7 & 8) The problem with trying to keep the law is that I didn’t really believe what the scriptures said concerning who we are in Christ. We are what Jesus is, the righteousness of God. The moment I began to actually believe the word; that Christ is in me, and I in Him, that I am righteous and holy, that I have His nature, is when my life actually began to change.
As long as we are trying to obey the law we are operating in the “flesh.” So the thing to “do” is believe. Believe who you are in Christ.