'My Flesh' in the Bible

For I know that nothing good lives in me, that is, in my flesh, for the desire to do good is present in my heart, but the ability to carry it out [consistently] is not.

Thank God [that I can be rescued] through [the power of] Jesus Christ our Lord. So then, I personally [try to] serve God's law with my mind, but [all too often] I serve the law of sin with my flesh [i.e., submitting in weakness to my human desires].