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.
and sprinkling of the blood of Jesus Christ: This is an allusion to the Old Testament (Exodus 24:8), but the allusion finds its fullest expression in the new. (Consider Hebrews 10:22, Hebrews 9:19-23, and Romans 6:1-5.) Notice what he says next: We are being brought along by the Spirit not only unto obedience but also "unto the sprinkling of the blood." These two are set with one another. Obedience is the "human" part of man’s election, and the "sprinkling of the blood of Jesus Christ" is the "divine" part.