It is no more I that do it - This is evidently figurative language, for it is really the man that sins when evil is committed. But the apostle makes a distinction between sin and what he intends by the pronoun “I”. By the former he evidently means his corrupt nature. By the latter he refers to his renewed nature, his Christian principles. He means to say that he does not approve or love it in his present state, but that it is the result of his native propensities and passions. In his heart, and conscience, and habitual feeling, he did not choose to commit sin, but abhorred it. Thus, every Christian can say that he does not choose to do evil, but would wish to be perfect; that he hates sin, and yet that his corrupt passions lead him astray.
But sin - My corrupt passions and native propensities.
That dwelleth in me - Dwelling in me as its home. This is a strong expression, denoting that sin had taken up its habitation in the mind, and abode there. It had not been yet wholly dislodged. This expression stands in contrast with another that occurs, where it is said that “the Spirit of God dwells” in the Christian, Romans 8:9; 1 Corinthians 3:16. The sense is, that he is strongly influenced by sin on the one hand, and by the Spirit on the other. From this expression has arisen the phrase so common among Christians, in-dwelling sin.