But I say, walk by the Spirit, and you will not gratify the desires of the flesh.  For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do. – Galatians 5:16-17 ESV
Look how bold the apostle is–he denies free will outright! We cannot do what we want, however hard we try…. Even the grace of God has not made the will perfectly free…. In this life, spirit and flesh battle it out, neither one being able to eliminate the other, although the spirit does manage to tame the flesh against its will and subject it to itself. No one can claim to have a clean heart or to be cleansed from filth, for whatever my flesh does, I do…. In every work of ours we need the forgiving mercy of God.
Reformation Commentary on Scripture – Galatians, Ephesians (Downers Grove, IL; IVP Academic; 2011) p. 190