according to the foreknowledge of God the Father, in sanctification of the Spirit, that you may obey Jesus Christ and be sprinkled in his blood: Grace to you and peace be multiplied.
Through sanctification of the Spirit - The Holy Spirit, the third person of the Trinity. The Greek is, “by (ἐν en) sanctification of the Spirit;” that is, it was by this influence or agency. The election that was purposed by the Father was carried into effect by the agency of the Spirit in making them holy. The word rendered “sanctification” (ἁγιασμός hagiasmos) is not used here in its usual and technical sense to denote “the progressive holiness of believers,” but in its more primitive and usual sense of “holiness.” Compare the notes at 1 Corinthians 1:30. It means here the being made holy; and the idea is, that we become in fact the chosen or elect of God by a work of the Spirit on our hearts making us holy; that is, renewing us in the divine image. We are chosen by the Father, but it is necessary that the heart should be renewed and made holy by a work of grace, in order that we may actually become His chosen people. Though we are sinners, He proposes to save us; but we are not saved in our sins, nor can we regard ourselves as the children of God until we have evidence that we are born again. The purpose of God to save us found us unholy, and we become in fact His friends by being renewed in the temper of our mind. A man has reason to think that he is one of the elect of God, just so far as he has evidence that he has been renewed by the Holy Spirit, and so far as he has holiness of heart and life, and no further.