Reformation and Enlightenment thought gives primacy to personal integrity and purity, even if that makes you incapable of doing any good in the world. In fact, for many Protestant believers, the link between good action and Christian piety was almost entirely severed. Salvation came, they believed, not to those who displayed compassion and did things for the benefit of their fellow humans, but to those who sincerely accepted Christ into their lives. The Calvinists’ concept of pre-destination led them to believe that an all-knowing God must have decided who would be saved even before the creation of the world. And, as God’s reasoning is beyond the reach of mere human intellect, the saved need not have any virtues that we could recognise as such.
The problem for Christians of all sorts, then, was working out if they were one of the chosen or not. Western Christianity demanded a constant self-vigilance to guard against lapses into sin. You couldn’t simply observe the rituals of the faith. You had to constantly interrogate yourself: “Am I Sincere? Do I truly mean it?”
I think, however, the roots of this concern for purity may go much further back into the Old Testament, to Judaism. I know little about this, so I’m happy to be corrected, but much seems to be made in Jewish law of Tahara and Tumah, the states of spiritual impurity and Purity. Ritual washing, ablution, seems to be the means of achieving such purity and was necessary before approaching God in prayer. The Bible contains reference to purification after menstruation, sex, childbirth, the preparation of the dead for burial, and so on. (Sex and Death, unsurprisingly!) Ablution must form the basis for baptism, in Christian faiths.
Protestantism promoted the idea of having a personal, inner relationship with God through reading and contemplating the Bible, so the concern with an inward-looking moral cleanliness persisted, but now the simple, physical rituals of purification held no power. All that was left was the habit of fearful self-scrutiny, the yearning to be pure and good, but without the easy means of acquiring it or being certain that you had it.
In fact, Jesus, himself warns against the dangers of becoming too bound by a sense of your own piety and the need to preserve it. In the story of The Good Samaritan (Luke 10:25), both a priest and a Levite (a priest’s assistant) do not go to the aid of a man who’s been mugged and left lying by the road. The rules on ritual purity forbade priests from having contact with the dead (or with spilt blood, perhaps?) It is left to a hated Samaritan, presumably inherently an unclean creature, to come to the man’s aid.
Importantly, this is all part of a discussion on how to achieve “eternal life”: salvation. (I’m using the King James Version of the Bible, because its archaic language is more fun and more sonorous.) Jewish law states that you must “Love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself” (10:27) Asked, then, who one’s neighbour is, Jesus tells the parable. On finishing, Jesus asks, “Which now of these three, thinkest thou, was neighbour unto him that fell among thieves?” When he is given the answer, “He that shewed mercy”, Jesus replied, “Go, and do thou likewise.”
“Do,” not “Be…” Not “Identify as…” Do.