Sanctification is a work in us, not a work for us. It is a work in us, and there are two agents: one is the Worker who works this sanctification effectually—that is the Spirit—and the other, the Agent, the efficacious means by which the Spirit works this sanctification is—Jesus Christ and his most precious blood. Suppose, to put it as plainly as we can, there is a garment which needs to be washed. Here is a person to wash it, and there is a bath in which it is to be washed. The person is the Holy Spirit, but the bath is the precious blood of Christ. It is strictly correct to speak of the person cleansing as being the sanctifier—it is quite as accurate to speak of that which is in the bath and which makes it clean as being the sanctifier too. Now, the Spirit of God sanctifies us. He works it effectively. But he sanctifies us through the blood of Christ, through the water which flowed with the blood from Christ’s side.1
Charles H. Spurgeon
2 according to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ and for sprinkling with his blood:May grace and peace be multiplied to you.