Romans 7:14–25 (NKJV)
14 For we know that the law is spiritual, but I am carnal, sold under sin. 15 For what I am doing, I do not understand. For what I will to do, that I do not practice; but what I hate, that I do. 16 If, then, I do what I will not to do, I agree with the law that it is good. 17 But now, it is no longer I who do it, but sin that dwells in me. 18 For I know that in me (that is, in my flesh) nothing good dwells; for to will is present with me, but how to perform what is good I do not find. 19 For the good that I will to do, I do not do; but the evil I will not to do, that I practice. 20 Now if I do what I will not to do, it is no longer I who do it, but sin that dwells in me.
21 I find then a law, that evil is present with me, the one who wills to do good. 22 For I delight in the law of God according to the inward man. 23 But I see another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members. 24 O wretched man that I am! Who will deliver me from this body of death? 25 I thank God—through Jesus Christ our Lord!
So then, with the mind I myself serve the law of God, but with the flesh the law of sin.