What do justification and sanctification mean?
1 Peter 1:1–2
To God’s elect…who have been chosen according to the foreknowledge of God the Father, through the sanctifying work of the Spirit, to be obedient to Jesus Christ and sprinkled with his blood: Grace and peace be yours in abundance.
To those who are elect…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.
Though justification and sanctification are both blessings of grace, and though they are inseparable, yet they are distinct acts of God; and there is, in various respects, a wide difference between them. The distinction may be thus expressed.—Justification respects the person in a legal sense, is a single act of grace, and terminates in a relative change; that is, a freedom from punishment, and a right to life; sanctification regards him in a physical sense, is a continual work of grace, and terminates in a real change, as to the quality both of habits and actions. The former is by a righteousness without us; the latter is by holiness wrought in us. That precedes as a cause; this follows as an effect. Justification is by Christ as a priest, and has regard to the guilt of sin; sanctification is by him as a king, and refers to its dominion. The former deprives of its damning power, the latter of its reigning power. Justification is instantaneous and complete in all its subjects; sanctification is progressive and perfecting by degrees.
Abraham Booth (1734–1806). An English Baptist minister, Booth served as pastor of Prescot Street Church in Whitechapel, London for 35 years as well as founding what is now Regents Park College for ministerial training in Oxford. He is most known for his work The Reign of Grace (from which this quote is taken).
From The Reign of Grace: From its Rise to its Consummation (Glasgow: Collins, 1827), 247–248.
[Note that the sanctification word-group in the New Testament commonly refers to what is nowadays often called positional or definitional sanctification.]
“Justification” and “Sanctification” in Concise Theology, by J. I. Packer.
Grant, Almighty God, that as we carry on a warfare in this world, and as it is thy will to try us with many contests,—O grant, that we may never faint, however extreme may be the trials which we may have to endure: and as you have favored us with so great an honor as to make us the framers and builders of thy spiritual temple, may everyone of us present and consecrate himself wholly to thee…so that thou mayest be worshipped among us perpetually; and especially, may each of us offer himself wholly as a spiritual sacrifice to thee, until we shall at length be renewed in thine image and be received into a full participation of that glory, which has been attained for us by the blood of your thy only-begotten Son. Amen.
John Calvin (1509–1564). A theologian, administrator, and pastor, Calvin was born in France into a strict Roman Catholic family. It was in Geneva however where Calvin worked most of his life and organized the Reformed church. He wrote The Institutes of the Christian Religion, the Geneva Catechism, as well as numerous commentaries on Scripture.
From Calvin's Bible Commentaries: Habakkuk, Zephaniah, and Haggai, translated by John King (Forgotten Books, 1847), 251.