Romans 7:15-19 New Revised Standard Version (NRSV)
15 I do not understand my own actions. For I do not do what I want, but I do the very thing I hate. 16 Now if I do what I do not want, I agree that the law is good. 17 But in fact it is no longer I that do it, but sin that dwells within me. 18 For I know that nothing good dwells within me, that is, in my flesh. I can will what is right, but I cannot do it. 19 For I do not do the good I want, but the evil I do not want is what I do.