Galatians 2:15-21

Galatians 2:15-21 
English Standard Version (ESV)

  If I hire someone to move my couch, and when they arrive, they spend the entire day sitting in a recliner, watching as I struggle to move my own couch, then why did I hire them?
  Or what if I use an Uber, but when the Uber arrives, I get in the car and drive and have the Uber driver sit in the backseat?  What's the point of having an Uber driver if you do that?
  This is the argument that Paul is making.  If it were possible for us to be saved through the Law, then Christ would not have been necessary.  It is faith in Christ that saves us, and Christ is absolutely necessary for us to achieve salvation.  Therefore, we live by faith, fully dependent on Christ (and Christ alone) for our hope beyond the grave.  We have been joined with him in his death, and are therefore joined with him in his resurrection, so we look forward with excitement.  Let us, therefore, depend on him and him alone, without adding burdens to those trying to live by faith.