Moreover, at the risk of being suspected of predestinarianism, I insist on another reason why the Spirit does not entirely purge the soul at the new birth. The impartation of spiritual life to a dead soul is wrought by the Spirit alone without the soul's co-operation, though it is active in conversion, but passive in regeneration. Theologians would call the first a case of synergism and the second an instance of monergism. If our distinction between these works of the Spirit is correct, it affords a sufficient reason why entire sanctification could not be wrought by the Spirit at the time of the new birth. The old man cannot be crucified without the co-operation of the new man. He must sign the death warrant of that sin in the flesh which the Son of God by His sacrifice for sin has condemned, in order to make that condemnation effectual for the destruction of "the body of sin" (Rom. vi. 6).
— from The Gospel of the Comforter, Chapter 14.